Clinical and genetic analysis of a child with hyperekplexia / 中华神经科杂志

Objective:To analyze the clinical phenotype and gene sequencing results of a child with hyperekplexia, and to clarify her genetic etiology.Methods:The clinical information of the child was collected, and the whole exome sequencing of the child and her parents was performed. The suspected pathogenic variants were verified by Sanger sequencing and bioinformatics analysis.Results:There was a 12 years old girl, who was hospitalized in the Department of Pediatric Neurology of Linyi People′s Hospital because of "paroxysmal limb stiffness for more than 11 years and aggravated for half a month" on July 4, 2022. The girl showed exaggerated startle reflexes and generalized siffness in response to external sudden, unexpected stimuli, occasionally accompanied by apnea and cyanosis, frequent attacks occurred several times a day, lasting for 1-30 minutes, and early head and abdomen flexion can be relieved. She showed normal growth and development, no abnormality in brain magnetic resonance imaging and video electroencephalogram during seizure. The whole exome sequencing showed that there was a missense heterozygous mutation c.643T>C(p.W215R) in the SLC6A5 gene of the child. Neither of the parents carried this mutation, which was a novel and de novo variant. According to the guidelines of American College of Medical Genetics and Genomics, this variant was a likely pathogenic variant [PS2: de novo (both maternity and paternity confirmed) in the patient with the disease and no family history; PM2: undetected variants in the normal population; PP3: multiple softwares predicted that this mutation would have harmful effects on genes or gene products], and highly conserved. Swiss modeling found that the hydrogen bond of the modified amino acid also changed. Conclusions:Hyperekplexia is relatively rare and prone to misdiagnosis. The main clinical features are excessive startle reflexes (limb shaking, or jumping) to unexpected external stimuli, resulting in overall stiffness, normal growth and development, and normal video electroencephalogram during the seizure. The likely pathogenic heterozygous missense variant c.643T>C (p.W215R) of SLC6A5 gene is the genetic cause of this case.

Proposal of conditional random inter-stimulus interval method for unconstrained enclosure based GPIAS measurement systems

Gap prepulse inhibition of acoustic startle (GPIAS) method has been used effectively for the objective assessment of tinnitus in animals. Among two types of enclosures for the GPIAS, the unconstrained type carries less risk of animal death due to the absence of binding stress in the enclosure, and lack of need for alteration to animal size variation as it grows. However, animals' voluntary movements, which have no relation to the startles evoked by acoustic stimuli, are problematic, as they cannot be excluded in the case of the unconstrained enclosure based GPIAS measurement system. In order to discount voluntary movements which are not associated with external acoustic stimuli, we propose the conditional random interstimulus interval (CR ISI) method for unconstrained enclosure based GPIAS measurement. With the proposed ISI method, the unconstrained enclosure based acoustic startle response measurement system has been implemented in this paper. As a result, the effectiveness of the proposed CR ISI method has been verified and compared with those of conventional ISI methods through animal experiments using SD-rats. The experimental results showed that abnormal startle responses and invalid GPIAS values caused by motion were prevented when our proposed CR ISI method was applied to our implemented system. It was also verified that our proposed CR ISI method is advantageous in reducing the total experimental time for acquiring normal startle responses and valid GPIAS values, compared to conventional ISI methods, since our proposed CR ISI can begin the acoustic stimulation only when the animal gets stable and motionless.

Influence of gender and age on auditory startle reflex in healthy adults / 中华行为医学与脑科学杂志

Objective To explore the influence of gender and age on auditory startle reflex in healthy adults.Methods A total of 150 healthy volunteers (92 males and 58 females) aged from 18 to 60 years were recruited for this study.A modified startle reflex paradigm was adopted.Furthermore,gender-age differences on startle magnitude,habituation,perceived spatial co-location induced prepulse inhibition (PSC-PPI) and perceived spatial separation-induced prepulse inhibition (PSS-PPI) in healthy volunteers were analyzed.Results ① There was no significant difference in amplitude and habituation of startie reflex between males and females (F=0.29,P=0.593;F=1.57,P=0.212).PSC-PPI and PSS-PPI were significantly higher in males (PSC-PPI:(34.68± 20.81) ％,PSS-PPI:(44.56 ± 23.19) ％) than those in females (PSC-PPI:(23.11±22.43)％,PSS-PPI:(35.21±25.09)％) (F=9.48,P=0.002;F=4.76,P=0.031).② There was a negative correlation between startle magnitude and age (r=-0.29,P＜0.01),however,no obvious correlations between age and PSC-PPI or PSS-PPI as well as habituation were observed.③Bivariate analysis of variance showed that no interaction between gender and age was found to the indexes of startle reflex(F=0.71-1.36,all P＞0.05).Conclusions There are differences for gender and age in the indexes of startle reflex.In detail,age chiefly influences startle magnitude,while gender mainly affects the prepulse inhibition.

Electrophysiological and clinical characteristics of children with startle epilepsy / 临床儿科杂志

Objective To investigate the characteristics of ictal and interictal electroencephalogram (EEG) and clinical manifestation in children with startle epilepsy. Methods The age of onset, inducing factors, the types of attacks, EEG features, cognitive function, treatment and prognosis were retrospectively analyzed in 8 cases of children with startle epilepsy from June 6, 2012 to March 2016. Results In 8 cases, 3 cases were male and 5 were female. The onset age was from 2.3 to 8.1 years old. The forms of onset were varied from generalized (tonic, myoclonic, atonic) to partial seizures (the asymmetry of posture rigidity, spasm). The most common ictal EEG finding was a diffuse electrodecremental pattern (5 cases), and the interictal EEG showed a large number of multifocal, generalized spines, slow waves and multiple spinous waves. There was one case with no history of brain injury while the other 7 cases had a history of brain injury. There were 7 cases with imaging abnormality, and the lesions of the frontal, parietal and temporal regions were indicated with a partial cerebral softening and brain atrophy. In 7 cases, all children had abnormal mental and motor development, and 1 case had normal cognitive function. The 7 cases with shock epilepsy showed no obvious response to the treatment of multiple antiepileptic drugs, and 1 case had no clinical onset after 2 months of treatment with VPA. Conclusions Startle epilepsy is mostly symptomatic, and few are non-symptomatic. The former had history of brain structure abnormalities, certain degree of motor retardation and mental disability, and no clinical response to antiepileptic drug therapy. The latter had basically normal cognitive function, and antiepileptic drug VPA treatment is effective. The degree of interictal epileptic was not an indicator of cognitive impairment and prognosis in children with startle epilepsy.

Clinical and genetic analysis of hyperekplexia in a Chinese child and literature review / 中华儿科杂志

Objective@#To investigate the clinical and genetic features of a Chinese child with hyperekplexia and review the related literature.@*Method@#The clinical and genetic data of one patient with hyperekplexia, who had visited the department of Pediatrics, Peking University First Hospital in July 2012, were analyzed. "Hyperekplexia" "startle disease" "GLRB" were used as key words to search at CNKI, Wanfang and PubMed from the database from creation to August 2016.@*Result@#The one-year-old female patient showed exaggerated startle reflexes and generalized stiffness in response to external sudden, unexpected stimuli at 2 hours after birth, which existed every day. Her younger twin sister died of severe apnea due to a continuous generalized stiffness at the age of 7 months. Physical examination exhibited the positive nose-tapping reflex. There were no obvious abnormalities in laboratory tests, electroencephalogram (EEG) and neuroimaging tests. The patient was revealed to have compound heterozygous mutations in GLRB gene, c. 298-1G>A (or IVS4-1G>A) inherited from the father and c. 347T>C (p. L116P) inherited from the mother. The mutation L116P in GLRB gene was not reported before. During the follow-up until 5 years old, the girl′s symptoms of startle reflexes and generalized stiffness were controlled with clonazepam treatment. Her mental development was normal, but she walked very carefully as wide-based gait to avoid of external sudden stimuli. Literature retrieval obtained 8 reports (all in English) with 39 GLRB-related cases. Combined analysis of the data of the 39 foreign cases and our case showed that the onset age of all 40 cases was in neonatal or in utero, and all presented exaggerated startle reflexes and generalized stiffness in response to external stimuli. Other symptoms included neonatal apneas (83%, 20/24), falls (56%, 15/27) and squint (42%, 10/24) etc. EEG (13/13) and brain imaging (90%, 28/31) were normal, or unrelated/nonspecific to hyperekplexia. In the total 17 mutations of GLRB gene found in 28 cases, the most frequent mutations were GLRB gene M177R (9 cases) and IVS5+ 5G>A (5 cases). Most cases (82%, 32/39) had received the treatment of clonazepam. The symptoms of hyperekplexia all could be improved in different degree after treatment, and 84% (32/38) of the cases were completely controlled or only existed exaggerated startle reflexes. The psychomotor development could be normal (13 cases) or retarded (25 cases).@*Conclusion@#The patient presented typical clinical manifestations of hyperekplexia and had a good response to clonazepam. The patient carried GLRB gene mutations found by genetic analysis, and was finally diagnosed with hyperekplexia. The younger twin sister died due to lack of timely diagnosis and treatment, suggesting the significance of early detection and proper treatment for this disease.

The establishment of positive and negative evaluative conditioning reflex of neutral facial expression / 中华行为医学与脑科学杂志

Objective To examine the effect of positive and negative evaluative conditioning (EC) on neutral faces.Methods The experiment consisted of three phases:baseline phase,conditioning phase,and re-evaluative phase,in which 41 college students participated,watching sequences of neutral faces (CS) pairing to either a positive stimulus (USpos) or a negative stimulus (USneg).Their emotional experiences (valence and arousal) and physiological reactivity (eyeblink startle reflex and skin conductance) were recor ded.Results (1) In the re-evaluative phase,CSpos was rated significantly more positive than CSneg and CSneut,while CSneg was rated significantly more negative than CSneut (CSpos (5.05± 1.24),CSneg (3.73± 1.48),CSneut (4.46± 1.04),P＜0.05).(2)In the re-evaluative phase,the mean startle eyeblink response magnitude(T score) to CSpos was significantly smaller than the responses elicited by CSneg and CSneut (CSpos (45.04±5.56),CSneg (51.44±9.30),CSneut (54.52± 10.60),P＜0.01).Conclusion The findings suggest that neutral faces can acquire valences and approach motivation through EC.

Modulación del reflejo de sobresalto en población colombiana: evidencia de la interacción entre emoción y motivación / Modulation of Startle Reflex in Colombian Population: Evidence of the Interaction between Emotion and Motivation

El objetivo de esta investigación fue comprobar el fenómeno de priming motivacional, observado a través de la modulación del reflejo de sobresalto en población colombiana. Participaron 73 estudiantes universitarios (38 hombres y 35 mujeres), los cuales fueron expuestos a 21 imágenes del Sistema Internacional de Imágenes Afectivas y a un estímulo sonoro de sobresalto de 105 dB. Se midió la electromiografía del músculo orbicular del ojo para evaluar la magnitud del reflejo de sobresalto. A través de un ANOVA de medidas repetidas, se encontró que la valencia de las imágenes modula la magnitud del reflejo de sobresalto (p < 0.0001, η² = 0.41) independientemente del sexo de los participantes. Se concluye que el fenómeno de priming motivacional también se presenta en esta población y que la metodología de la modulación del reflejo de sobresalto puede ser utilizada de forma confiable en ella.

The objective of this research was to test the phenomenon of motivational priming observed through the modulation of the startle reflex in Colombian population, involved 73 university students (38 men and 35 women) who were exposed to 21 pictures of the International Affective Pictures System and a sound startle stimulus of 105 dB. Electromyography of the orbicularis oculi of the eye was measured to assess the magnitude of the startle reflex. Through repeated measures ANOVA we found that the pictures valence modulates the magnitude of the startle reflex (p < 0.0001, η² = 0.41) and that modulation does not depend on the sex of the participants. It is concluded that motivational priming phenomenon occurs also in this population and this methodology can be used reliably in this population.

Modulation of the startle response in verbal aggressors: differences among stimuli with distinct affective social content

The emotional response to socially affective stimuli is an important variable to understand aggression. Research is lacking on the psychophysiological basis of verbal aggressiveness that would allow the identification of these emotional responses. The aim of the present study was to investigate modulation of the startle response in verbal aggressors during the presentation of visual stimuli with different affective social content. Acoustic startle probes were administered to 29 verbal aggressors and 28 non-verbal aggressors while viewing slides from the International Affective Picture System, which contains sexual, filial, neutral, unpleasant, and suffering of others pictures. Verbal aggressors showed a low startle response to sexual pictures compared with non-verbal aggressors and a potentiated startle response to neutral pictures compared with unpleasant, filial, and suffering of others pictures. These differences were observed among women. Based on previous studies, the present results may be explained by high testosterone levels, low cortisol levels, and moral disengagement exhibited by verbally aggressive women...

Novel GLRB gene mutation in a Saudi baby with hyperekplexia.

Aim: We aim to describe a case of hyperekplexia in a Saudi neonate due to Novel mutation in GLRB. Case Presentation: One month old Saudi neonate with hypertonicity, repetitive episodes of jitteriness and exaggerated startle reflex. Discussion: Hyperekplexia (OMIM:149400, 138492 & 604159) is considered a rare, autosomal dominant neurological disorder that presents early in life with hypertonicity, exaggerated startle response and life threatening neonatal apnea. It has been caused by mutation in the alpha-1subunit (GLRA1) on chromosome 5q32, Beta subunit (GLRB) gene on chromosome 4q31 of the inhibitory glycine receptor and GLYT2 gene (SLC6A5) on chromosome 11p15 which encodes a presynaptic glycine transporter. Conclusion: Raising awareness of the presence of this treatable disease may prevent unnecessary exposure to anti-epileptic medications, prevent life threatening apneas and improve long term outcome.

A preliminary study of single prolonged stress influence acoustic startle reflex and prepulse inhibition in rats / 中华行为医学与脑科学杂志

ObjectiveTo explore the deficits of acoustic startle reflex (ASR) and prepulse inhibition (PPI) of acoustic startle reflex in single prolonged stress rats.MethodsSixty Sprague Dawley rats were randomly divided into control 1,7,14 d groups and stress 1,7,14 d groups.All stressed rats received single prolonged stress while all control rats were left in their home cage.Behavioral changes in these rats were analyzed in ASR and PPI paradigm.ASR and PPI were carried out on day 2,8,15,respectively.ResultsThere were no differences of ASR and PPI among control 1,7,14 d groups (P ＞ 0.05).ASR of stress 1 d group ( (92.49 ± 31.54) g) was higher than that of control 1 d group((64.48 ± 17.95)g,P＜0.05) while PPI of stress 1 d group((28.60 ±29.02)％) was lower than that of control 1 d group( (41.60 ± 15.10)％,P ＜ 0.05 ).There were no differences of ASR between control 7 d group and stress 7 d group,control 14 d group and stress 14 d group (P＞ 0.05 ).Compared with control 7 d group ( (41.30 ± 12.79) ％ ),PPI in stress 7 d group ( ( 17.95 ± 31.79) ％ ) was reduced (P ＜ 0.05 ).Compared with control 14 d group ( (41.16 ± 12.25 ) ％ ),PPI in stress 14 d group( ( 13.71 ± 32.48) ％ ) was reduced (P ＜ 0.05).ConclusionEffects of stress on ASR in rats increased in early period,while the impaired PPI may last for a long time.

Establishment of delay-trace conditioning procedure of classical eyeblink conditioning in Kunming mice and analysis of behavioral characteristic parameters / 中华行为医学与脑科学杂志

ObjectiveTo investigate the characteristic parameters and variation of acoustic startle reflex (ASR) and conditioning response (CR)during the acquisition of delay-trace eyeblink conditioning.Methods15healthy Kunming mice were randomly divided into 3 groups:single-task DEBC group ( n =5 ) ; single-task TEBC group ( n =5) ; dual delay/trace group ( n =5).Three groups received paired training of tone conditioned stimulus(CS)in different audio frequency (TEBC groups:2KHz; DEBC group:1KHz) and a 100 ms comeal oxygenpuff unconditioned stimulus(US).Then observed the characteristic parameters of ASR and CR.ResultsAfter pairing training for 10 days,ASR rate( ASR％ ) of single-task groups ( 10th day (38.00 ± 8.64) ％ and (38.55 ±12.41 ) ％ respectively,time effect:F =4.574,P =0.008 ; group effect:F =2.021,P =0.193 ) and dual delaytrace group ( 10th day (47.95 ± 14.23 ) ％ and (62.01 ± 9.03 ) ％ respectively,time effect:F =5,547 P =0.013 ;group effect:F =0.738,P =0.415) changed significantly with the following training but between single-task groups or dual delay-trace group.CR rate ( CR％ ) of single-task groups ( 10th day were (45.4 ± 5.39) ％ and (65.6 ± 6.77) ％ respectively,time effect:F =9.558,P =0.000 ; group effect:F =5.117,P =0.054 ) and dual delay/trace group ( 10th day (57.66 ± 4.34) ％ and (77.35 ± 7.36) ％ respectively,time effect:F =7.750,P =0.002 ;group effect:F=1.449,P=0.263 ) showed obvious change with the following training but between singletask groups or dual delay-trace group.Peak amplitude of single-task DEBC group ( time effect F =2.679,P =0.017 ) and dual delay-trace group ( F=3.452,P=0.034 ) had increased significantly with the following training.Peak latency showed no obvious change.ConclusionDual delay-trace conditioning procedure of classical eyeblink conditioning and single-task can be successfully established in Kunming mice.Although there are some variations,those can be controled and be weaken effect of them by taking targeted measures.

Comparative study on prepulse inhibition of the startle reflex between pure cerebral concussion and multiple cerebral concussion model rats / 中华行为医学与脑科学杂志

ObjectiveTo observe the prepulse inhibition(PPI) ot the startle reflex of pure cerebral concussion (PCC) suffered from one concussion and multiple cerebral concussion (MCC) suffered from three concussions in rats,and to explore accumulate effect upon cognitive dysfunction of MCC.MethodsA metallic pendulum striker device for closed head injury was employed to duplicate PCC and MCC models in Stragu-Dawley rats.The MCC rats were hit three times on rats'head and it is interval 24 hours for every hit.According to the criteria of cerebral concussion,the investigated animals were divided into PCC group and MCC group at freedom.One control group was used.Each group included 10 animals.Each experience mental animal was tested from 3 days pre-injury to 28 days post-concussion.Startle reflex amplitude (for P values),pre-stimulation induced reflex amplitude on three standard stimulations,that was,67dB,69dB and 73dB (for PP67,PP69 and PP73 values) and prepulse inhibition of the startle reflex (PPI) were collected.ResultsThe P values and three PP values in the first three days of pre-replication experiment,there was no statistical significance in each group.However the P values and PP67,PP69 and PP73 values declined until to the 16th day after injury (P＜0.05),then recovered in PCC group.The P value and PP67,PP69 and PP73 values changes of MCC group declined and not recovered until to test end (P＜0.05 ) and they were more lower than PCC.The three PPI values were a little bit increase in both groups,there were statistics significance at some test points (P＜0.05) compared with control.ConclusionThe startle reflex amplitude and pre-stimulation induced reflex amplitude weaken after cerebral concussion and there is damaging accumulate effect to injury times,the PPI is enlanced by cerebral concussion.

Lesions of the medial prefrontal cortex of guinea pig inhibit acoustic startle reflex / 中华行为医学与脑科学杂志

Objective To observe and analyze the role of different subfields of medial prefrontal cortex (mPFC) in the expression course of startle reflex.Methods 24 healthy male British kind of albino guinea pigs were randomly divided into 4 groups:anterior cingulated cortex lesion ( n =6) and sham-lesion ( n =6) ( Experiment 1 ) ; prelimbic cortex lesion/joint lesion of prelimbic cortex and anterior cingulated cortex(n=6) and sham-lesion ( n =6) ( Experiment 2 ).The animals were injected lidocaine ( lesion ) or physiological saline ( sham-lesion ).Each group received paired training of conditioned stimulus( CS,a tone) and unconditioned stimulus (US,a air puff),to observe the acoustic startle reflex(ASR) change of these groups.Results As the results of experiment 1 suggested,SR rate did not change significantly after anterior cingulated cortex lesion ( time effect:F =15.421,P =0.098 ; group effect:F =14.753,P =0.084).As the results of experiment 2 suggested,SR rate did not change significantly after prelimbic cortex lesion ( time effect:F =14.975,P =0.178 ; group effect:F =18.643,P =0.089).When prelimbic cortex and anterior cingulated cortex were lesioned at the same time,SR rate declined significantly and didn ' t recover with the following training ( group effect:F =67.743,P =0.009 ).ConclusionLesions of the prelimbic cortex and anterior cingulated cortex in mPFC cause the significantly decline of acoustic startle reflex( ASR),which don' t recover with the following training.This study indicates that mPFC involves in the regulation of ASR,but the regulation mechanism needs to be discussed.

Prepulse Inhibition of Startle Response: Recent Advances in Human Studies of Psychiatric Disease

Prepulse inhibition (PPI) is considered to be one of the most promising neurophysiological indexes for translational research in psychiatry. Impairment of PPI has been reported in several psychiatric diseases, particularly schizophrenia, where PPI is considered a candidate intermediate phenotype (endophenotype) of the disease. Recent findings from a variety of research areas have provided important evidence regarding PPI impairment. Human brain imaging studies have demonstrated the involvement of the striatum, hippocampus, thalamus and frontal and parietal cortical regions in PPI. In addition, several genetic polymorphisms, including variations in the genes coding for Catechol O-methyltransferase, Neuregulin 1, nuclear factor kappa-B subunit 3 and serotonin-2A receptor were related to PPI; and these findings support PPI as a polygenetic trait that involves several neurotransmitter pathways. Early psychosis studies suggest that PPI disruption is present before the onset of psychosis. Also, discrepancy of PPI impairment between children and adults can be found in other psychiatric diseases, such as autistic spectrum disorders and posttraumatic stress disorder, and comprehensive investigation of startle response might contribute to understand the impairment of the neural circuitry in psychiatric diseases. Finally, recent studies with both Asian and Caucasian subjects indicate that patients with schizophrenia exhibit impaired PPI, and impaired sensorimotor gating might be a global common psychophysiological feature of schizophrenia. In conclusion, studies of PPI have successfully contributed to a better understanding of the fundamental neural mechanisms underlying sensorimotor gating and will certainly be most valuable in devising future approaches that aim to investigate the complex pathogenesis of psychiatric diseases.

Sistema automático de análise comportamental em pombos / Automatic behavioral analysis system in pigeons

Este trabalho apresenta o projeto e os testes de um equipamento para registro automatizado da amplitude e da latência da resposta de sobressalto acústico em pombos. O sistema desenvolvido é formado por uma câmara experimental, com uma célula de carga acoplada ao piso para ser utilizada como sensor de força, circuitos para geração de estímulos (luz, som ou choque) e circuitos de condicionamento e interfaceamento dos sinais a um microcomputador utilizado para controle, armazenamento e análise dos dados. O software para controle do sistema foi desenvolvido utilizando-se linguagem C para operar em plataformas DOS ou Windows, com rotinas de controle para o protocolo experimental (número, duração e taxa de repetição dos estímulos) e rotinas gráficas para apresentar as curvas de amplitude da resposta em relação ao tempo, armazenamento dos dados no disco e processamento. Os dados são armazenados em arquivos e podem ser analisados estatisticamente com outros aplicativos computacionais. Foram realizados testes comportamentais com pombos e ratos, expostos a 20 estímulos sonoros (1 kHz, 100 dBA, duração de 1 s e taxa de repetição de 30 s). Os animais do grupo controle permaneceram na caixa durante 30 minutos sem receber estímulos. A amplitude do sobressalto, medida em kgf, foi registrada durante 4 s e analisada em janelas temporais de 1 s imediatamente após o som. Os testes com ratos apresentaram resultados semelhantes aos da literatura e indicaram a eficiência do sistema. Comparativamente aos ratos, os pombos apresentaram menor amplitude e maior latência e indicaram diferenças comportamentais entre as duas espécies. O equipamento mostrou-se adequado para as investigações neurobiológicas e comportamentais que usam modelos animais.

This work presents the design and testing of an apparatus for automatic recording of the magnitude and latency of acoustic startle response in pigeons. This system includes one experimental chamber with a load cell coupled to its floor (which is used as a force sensorto measure the amplitude of the response to the stimulus), stimuli generation circuits (light, sound or shock) and interfacing circuits (to a microcomputer that is used for control, storage and data analysis). The software used to control the system was developed using C language and runs under DOS or Windows operational systems. There are routines to implement the experimental protocol (number, duration and repetition rate of stimuli) and graphics routines to show the amplitude of the startle response curves as a function of time. The data may be saved in the disk for further statistical analysis with other programs. Behavioral tests with exposure to 20 tone-pulses (1 kHz, 100 dBA, 1 s, every 30 s) were carried out with pigeons and rats. The control group animals remained in the chamber during 30 min without receiving any acoustic stimulation. The magnitude of startle was recorded (in kgf) during 4 s andanalyzed in temporal windows of 1 s. The tests with rats corroborate the literature and indicate the efficiency of the system. Compared to rats, the pigeons presented lower magnitude and longer latency of acoustic response, indicating behavioral differences between the two species. The equipment was considered adequate for neurobiological and behavioral investigations which use automatic recording of acoustic stimuli responses.

A Case Report of Congenital Hyperekplexia in Twin

Hyperekplexia or startle disease is a hereditary neurological disorder characterized by an abnormally exaggerated startle response to tactile, auditory and visual stimuli, together with a global muscular hypertonia and hyperactive tendon reflexes. This disease is a rare, genetically determined disorder, with an autosomal dominant inheritance with variable expression, first described by Suhren, et al. We report two cases of familial hyperekplexia, who developed hypertonia and pathologic startle response to tactile stimulation in the immediate neonatal period. The infant showed a marked improvement of the startle response and muscular hypertonia with low-dose clobazam.

Startle Epilepsy: Clinical Characteristics in 8 Patients

BACKGROUND: The focus of this paper was to determine the clinical characteristics of startle epilepsy characterized by reflex partial seizures of the sensorimotor cortex. METHODS: Eight patients with startle epilepsy were evaluated for their clinical seizure history, neurologic examination, MRI, routine EEG, video-EEG monitoring, and ictal SPECT. RESULTS: Etiologies were: perinatal injury (4 patients), kernicterus following hemorrhage during infancy (1), near-drowning at age 4 (1), and unknown (2). The age of seizure onset varied from several months to 16 years. All patients had spontaneous as well as reflex seizures. Effective triggers included several sensory modalities, typically proprioceptive and auditory. The stimuli should be sudden and unexpected. Seizures usually occurred daily and were medically intractable. Neurological examination was abnormal in 6 patients. Five had mental retardation, and 4 with motor deficit. MRI was abnormal in 6 patients, generally showing large encephalomalatic changes involving cortical and sub-cortical structures. Five had bilateral lesions. The semiology was characterized by unilateral or generalized tonic posture. Scalp interictal and ictal EEGs had limited value to lateralize the epileptogenic focus. Intracranial EEG in 1 patient who underwent surgery showed ictal onset on the lateral sensorimotor cortex. CONCLUSIONS: Startle epilepsy is a rare but distinctive epileptic syndrome characterized by reflex seizures triggered by unexpected sensory stimuli. Some clinical findings including etiologic events (kernicterus following hemorrhage, near-drowning), high incidence of bilat-eral lesions, ictal onset on lateral sensorimotor cortex without involvement of medial cortex, and ictal SPECT findings have not been reported or were different from previous studies.