Central nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy: a clinical, neurophysiological and radiological study

The frequency of the association between CIDP and CNS lesions is probably underestimated. To assess the frequency of CNS involvement in CIDP patients, and to study the characteristics of this possible association. Forty patients [20 males, and 20 females] aged between 19 and 50 years [mean 33.12 +/- 9.3 years] fulfilling the clinical, neurophysiological and CSF criteria of INCAT for the diagnosis of CIDP were submitted to complete general and neurological assessment, laboratory investigations, CSF analysis, neurophysiological evaluation [NC studies, evoked potentials [VEPs, BAEPs, SSEPs]], and MRI brain and spinal cord. Clinical evidences of CNS involvement were recorded in 12 patients [30%] of CIDP patients, abnormally delayed VEPs latencies were recorded in 16 patients [40%], abnormal BAEP latencies in 12 patients [30%], abnormal SSEP latencies in 22 patients [55%], and abnormal latencies in more than one modality in 13 patients [32.5%], MRIs brain and spinal cord were abnormal in 10 patients [25%]. CIDP patients with clinical and/or radiological evidences of CNS involvement had a significantly younger age of disease onset, more frequent relapsing-remitting pattern of the disease course, more prolonged disease duration, and less favorable response to therapy than those without evidences of CNS involvement. CIDP patients with delayed evoked potentials' latencies and/or MRI demyelinating lesions were more frequent in CIDP patients with clinical evidences of CNS involvement. Moreover, MRI lesions were more frequent in those having abnormal visual evoked potential responses. Finally, there was a percentage of CIPD patients who showed a subclinical central neurophysiological and/or radiological abnormalities. CIDP is frequently associated with various clinical, neurophysiological and radiological evidences of CNS involvement. MRI and evoked potentials are useful non-invasive techniques for demonstrating this association

Vestibular evoked myogenic potentials in multiple sclerosis

Vestibular evoked myogenic potential [VEMP] is an otolith-mediated, short-latency reflex recorded from the sternocleidomostoid muscle in response to intense auditory clicks used for evaluation of the vestibulo-spinal pathway. This study aimed at shedding light on the sensitivity of VEMPs in detection of occult vestibular pathway lesions in patients suffering from multiple sclerosis [MS]. VEMPs were recorded from 25 MS patients. Clinical data were evaluated for possible brain stem affection, their EDSS scores were recorded. All patients underwent visual evoked potential [VEP], brainstem auditory evoked potential [BAEP], somatosensory evoked potential [SSEP] studies and magnetic resonance imaging [MRI]. VEMPs were also recorded in 25 age and sex matched controls as well. VEMPs showed abnormal P13 and N23 waves in 56% of Patients, VEP in 56%, BAEPs in 44%, SSEPs in 28% and MRI in 80%. MRI showed better sensitivity in detecting brain stem plaques yet patients with normal MRI had abnormal VEMPs and BAEPs and VEMPs had nearly equal sensitivity in detecting brainstem plaques in symptomatizing group; however VEMPs were more sensitive than BAEPs in non symptomatizing group. Also we found no significant correlation between VEMPs and MRI or BAEPs. VEMPs is a simple, non-invasive, safe and quick method, which should be considered as a complementary neurophysiological tool for evaluation of possible brainstem dysfunction

electro-physiologic study of trigeminal brainstem circuits in migraine

The study aimed at investigating functional changes in the trigeminal and optic nerves brainstem connections in migraine patients. Trigeminal somatosensory evoked potentials [TSER's], electric blink reflex [EBR] and light stimulus evoked blink reflex [LBR] were carried out interictally on 18 patients suffering from migraine without aura and 12 healthy controls. TSER's latencies [N1, P1, N2, and P2], EBR latencies [R1, ipsilateral and contralateral R2] as well as LBR latencies [direct and indirect responses] and their amplitudes were recorded and compared to healthy controls. The ipsilateral and the contralateral R2 components of the EBR [R2i, R2c] showed a highly significant delay as compared to the control group [p<0.000]. N1, P1 and N2 latencies in patients were significantly longer than the control group bilaterally. P1 latencies showed the most significant prolongation of latency [p<0.0000]. The latencies of the LBR direct and indirect responses were significantly prolonged in the patient group [p<0.000] and had a double fold amplitude compared to those of the control group. Migraine patients show a disruption in the central circuits not only at the level of the brainstem but possibly within the higher cerebral regions as well

Retinal toxicity to triamcinolone acetonide's vehicle: an electrophysiology and electron microscopy study

To assess rabbit retinal toxicity to triamcinolone acetonide vehicle, benzyl alcohol, when injected intravitreally. This prospective comparative experimental study included 24 pigmented rabbits assigned into 2 groups; group 1 [experiment, n=12] received intravitreal 0.1ml of benzyl alcohol [BA], and group 2 [control, n=12] received intravitreal 0.1ml of balanced salt solution [BSS]; all injections were done in the right eyes. Clinical examinations were done on both eyes of all available rabbits before injection, at 1 and 3 hours post injection, and together with electroretinograms [ERGs] at 3, 7, 14, 28 and 42 days following injections. Three rabbits from each group were killed at 7, 14, 28 and 42 days and both eyes were sent for either light or electron microscopic examination for quantitative morphometric measurements. Mean amplitudes of ERG a and b waves of the BA-injected eyes were 6.42 +/- 9.02 micro v and 11.18 +/- 15.18 micro v at 3 days respectively, which was significantly reduced compared to the BSS-injected eyes [30.87 +/- 8.22 micro v and 57.90 +/- 13.38 micro v, respectively; p<0.01 t-test] and the non-injected contralateral eyes [36.20 +/- 7.85 micro v and 64.10 +/- 9.36 micro v, respectively; p<0.01 t-test]. These ERG responses continued to be significantly reduced in the BA-injected eyes [p<0.01 t-test] of the unkilled rabbits up to 6 weeks. The mean ganglion cell count [at a magnification of X200 in a standard frame of 4740.32 micro m[2]] were significantly reduced [p<0.005 t-test] in the BA-injected eyes [8.42 +/- 2.4] compared to the BSS- and non-injected eyes [16.42 +/- 3.9 and 16.5 +/- 4.2, respectively]. The mean inner nuclear layer [INL] and outer nuclear layer [ONL] thickness were significantly reduced [p<0.005 t-test] in the BA-injected eyes [3.78 +/- 0.96 micro m and 11.77 +/- 1.29 micro m, respectively] compared to the BSS- [6.1 +/- 0.92 micro m and 21.82 +/- 0.95 micro m, respectively] and non-injected eyes [7.05 +/- 1.9 micro m and 22.49 +/- 1.0/micro m, respectively]. Electron microscopy showed intracellular irreversible changes in the GCL, INL, ONL, and PRL at 6 weeks in group 1, with no significant changes in group 2. There was no significant rise in the intraocular pressure or clinical evidence of increased lens density during the study period. Triamcinolone Acetonide's Vehicle, benzyl alcohol, produced severe irreversible ERG and structural damage to rabbit neurosensory retinal following intravitreal injection

Anophthalmia/microphthalmia: clinical, ophthalmological and imaging findings

This study described the craniofacial anomalies in correlation with ocular, intracranial, cytogenetic and electro- physiological findings in children with anophthalmia/microphthalmia. Twenty cases with congenital anophthalmia/microphthalmia [11 males, 9 females with age range from 8 days to 9.5 years] were examined. Seventeen cases had bilateral clinical anophthalmia/microphthalmia, while three cases had unilateral microphthalmia/anophthalmia. Patients with clinical anophthalmos/microphthalmia had associated congenital brain malformations [10/20 patients, 50%], genital anomalies [6/20, 30%] and major congenital orodental abnormalities [2/18 patients, 11.1%]. Eight cases of 11 with bilateral microphthalmia [72.7%] were reported to have bilateral congenital cataract. In addition, 6 cases [6/10, 60%] had abnormal visual evoked potentials [VEP] and electroretinogram [ERG]. The results presented the correlation between VEP and clinical, neuroimaging picture and/or the ophthalmological abnormalities. Eye defects are heterogeneous, since they were observed in clinical patterns with all modes of inheritance. Autosomal-recessive syndromes represent 55% of total syndromes, followed by syndromes of autosomal-dominant inheritance [15%], X- linked dominant [10%], chromosomal structural abnormalities [10%] and caused by environmental agents [10%]. Nevertheless, high rate of consanguinity [11 cases, 55%] with mean inbreeding coefficient of 0.0512 and the similarly affected sibs highlight the role of single gene disorder in the country. The contribution of electrophysiology of the eye, MRI of brain, cytogenetic and orodental examinations were useful for better determination of visual function and identification of potential underlying multisystem disease, subsequently, improving parental understanding and genetic counseling