Exhausting fatigue influences F-wave and peripheral conduction velocity, following lumbar radiculopathy.

PURPOSE: The purpose of the study was to determine whether mechanical nerve root compression could indirectly contribute to early muscle fatigue because of impaired activation. METHOD: The patients' two legs and the control group's dominant leg were subjected to exhausting foot dorsiflexion against 2 kg weight. Electrophysiological parameters were measured under three conditions: before, upon completion of, and five minutes after the exhausting effort (i.e. causing unbearable fatigue). The study was performed in a warm room (24 degrees C), in the EMG laboratory of a rehabilitation centre using standard equipment. Eighteen patients participated in the study (12 males and six females, mean age 47.8 +/- 12.0 years). They suffered from lumbar radiculopathy and unilateral complaints at the L4, L5 innervation territory. There were 22 matched controls (18 males and 4 females, mean age 44.4 +/- 9.9 years) that were healthy subjects. The patients' two legs and the dominant leg of the control participants were tested. The peroneal nerve was stimulated supra-maximally, behind the fibular head. Recording the activity of the anterior tibial muscle served to calculate F-wave latency, the conduction velocity of the nerve and muscle complex (NMCV), the compound muscle action potential (CMAP) amplitude and the exhaustion time. RESULTS: Following the exhausting fatigue, the symptomatic, asymptomatic, and control legs exhibited a significant decrease in NMCV and reduced CMAP amplitude (p < 0.05). In each condition (rest, effort, recovery), the patients' two leg types exhibited similar NMCV (symptomatic vs asymptomatic), yet each of these two types was significantly slower than the controls' NMCV. A significant prolongation of F-wave latency after an exhausting effort was found in the symptomatic legs. CONCLUSIONS: Our results suggest that a continuous exhausting effort impairs F-wave latency and NMCV, presumably by decreasing the proportion of fast conducting nerve fibres. Peroneal nerve root compression can contribute to early fatigue of the respective muscles.

Cervical spine movements in hemiparetic patients.

Cervical spine movements in 38 severe hemiparetic patients were measured, at least 6 months after the breakout of the first and unique cerebral vascular accident. The purpose was to investigate if there was any difference in maximal head rotation and lateral bending movements between the plegic and the sound side. The measurements were taken by a spherical compass attached to a cubic protractor with a small mobile ball inside, both fixed to the patient's head. All the tests were done several months after the end of the rehabilitation process and compared to those obtained in 29 orthopaedic patients without hemiparesis (control group). The results obtained demonstrate that the cervical spine movements in hemiparetic patients are minimally limited and manifested only in lateral bending towards the sound side (p = 0.042). The difference was more significant after 1 year or more of hemiparesis (p = 0.013). In the control group the differences in the external rotation angle and lateral bending angle between the right and left sides were not significant.

The vestibulo-ocular reflex and dysequilibrium after hemispheric stroke.

Patients with hemispheric lesions frequently suffer from equilibrium impairment that may be prolonged and may interfere with rehabilitation. In an effort to clarify whether this phenomenon is related to vestibular dysfunction, we examined the relationship of the horizontal vestibulo-ocular reflex (VOR) with stability in 15 patients with unilateral hemispheric stroke. The study included electro-oculographic recording of the VOR while the patients were rotated in a vestibular chair. Stability was scored in accordance with the patients' ability to maintain equilibrium in six graded positions. The findings demonstrated relationship between VOR gain (eye/head displacement) and equilibrium. It is suggested that the "loss of balance" after stroke may be related to an impairment of the corticovestibular modulation of the vestibular function.

Saccadic responses in patients with hemispheric stroke.

Saccadic characteristics were examined in 15 patients with unilateral hemispheric stroke. Eye movements were measured by a standard electro-oculogram technique. In patients with cortical infarcts, mean gain values were lower than in the control subjects for eye movements directed away from the infarct (contralateral), but higher for eye movements towards the infarct (ipsilateral) (p < 0.025). We suggest that impairment of efferent neural signals from the affected hemisphere of stroke patients may decrease excitation of the contralateral neural circuits and inhibition of the ipsilateral neural circuits of the brainstem saccade generator.

Vestibulo-ocular reflex suppression following hemispheric stroke.

This study examined vestibular function following hemispheric ischemic strokes, by testing the suppression of the vestibulo-ocular reflex (VOR). Fifteen patients with cortical or subcortical infarcts several months after a unilateral hemispheric stroke were compared with control subjects. The results indicated impairment of VOR suppression in patients with cortical infarcts. It is suggested that cortical infarcts may induce a mild and symmetrical impairment of vestibular activity which may be responsible for mild and transient imbalance in patients who undergo stroke.

Upper limb somatosensory evoked potentials as a predictor of rehabilitation progress in dominant hemisphere stroke patients.

BACKGROUND AND PURPOSE: The aim of this study was to determine the predictive yield of upper limb short latency somatosensory evoked potential (USEP) in patients with first stroke in the dominant hemisphere. METHODS: Nineteen patients (average age, 58 years) were evaluated twice: on arrival at the rehabilitation center, approximately 3 weeks after the stroke, and again approximately 10 weeks later. The clinical assessment included a quantitative evaluation of motor ability, independence in activities of daily living, and communication ability. USEP was recorded during the week of the initial clinical evaluation. Special attention was paid to the relations between USEP parameters and the dynamics of the clinical condition. RESULTS: The seven patients in whom no cortical potential could be detected showed the worst outcomes; however, the existence of cortical potentials in the remaining 12 patients did not provide a precise prediction of their "rehabilitative capacity" (ie, the extent of their progress). A correlation was established between the amplitude of the potentials recorded over both hemispheres and changes in communication ability. Additional findings included an association between shortened central conduction time over the damaged hemisphere during the first month after stroke and improvement in motor ability. CONCLUSIONS: USEP can serve as an adjuvant tool for predicting the recovery progress of stroke patients.

Course and outcome of patients in vegetative state of nontraumatic aetiology.

A follow up study is reported of 100 consecutive unconscious patients admitted to an intensive care coma facility with a history of 30 days or more of unconsciousness of nontraumatic cause. Twenty recovered consciousness, all within 5 months of injury. 31 of the remaining patients died within 6 months following injury, while 49 continued unconscious until death. The mean life expectancy of these 49 was 26-34 months from that time. All 20 patients who recovered awareness continued to suffer from major disability. The prognosis for life or death and for recovery or not of consciousness was not significantly correlated with age or aetiology of the vegetative state. Among those who recovered consciousness, the younger patients showed somewhat better results in three parameters of function: locomotion, ADL and day-placement, but not in cognition, behaviour or speech accuracy and fluency. The overall results for these nontraumatic patients with postcomatose unawareness are clearly worse than those for patients with a similar period of unconsciousness following craniocerebral trauma.

Symptomatic postprandial hypotension in high paraplegia. Case report.

Symptomatic postprandial decrease in blood pressure has been described in patients with various autonomic disorders, but not in patients with spinal injuries. Presented herein is a 31 year old female patient with traumatic complete paraplegia under the T3 level, in whom postprandial hypotension (PPH) was observed. The PPH was preceded by an increase in insulin level and was followed by an acceleration of heart rate. Oral caffeine prevented the hypotension and alleviated the symptoms. It is suggested that the PPH might be manifested as a result of damage to an upper thoracic spinal baroreflex. Clinical investigation of PPH is recommended for patients with high paraplegia.

Is the appearance of periarticular new bone formation related to local neurological disability?

The present work examined the relationship between the appearance of periarticular new bone formation (PNBF) and the presence of local sensorimotor disability, and the relationship between PNBF and the severity of the motor disability. The study population consisted of 18 patients with spinal cord lesions and 18 patients with traumatic brain injury. The confinement of PNBF below the level of neurological deficit in patients with spinal cord lesions, and mainly to paralysed or paretic limbs in brain injured patients, indicates a possible causal relationship between the presence of sensorimotor disability and PNBF. On the other hand, the high incidence of bilateral PNBF in patients with incomplete spinal lesions and the appearance of PNBF in some nonplegic and even paretic limbs in the brain injured patients, demonstrates the lack of connection between the severity of the motor deficit and the risk of PNBF. It is suggested that local factors which are related to sensorimotor disability are probably involved in PNBF induction, but additional elements may also play a role in the induction of PNBF and in its propagation.

Acute stroke patients: long-term effects of rehabilitation and maintenance of gains.

The efficacy of rehabilitation programs to facilitate recovery after acute stroke remains controversial. To further evaluate this issue, the records of 139 "middle-band" stroke survivors were reviewed retrospectively at admission to, discharge from, and one-year follow-up from inpatient rehabilitation. Patients were divided into two groups (out-patient [O/P] or no O/P) based on their involvement in physical and occupational therapy services. A repeated measures ANOVA indicated that both groups made clinically and statistically significant improvements in all functional indices between stroke onset, discharge from inpatient rehabilitation, and follow-up: O/P therapy: mobility F(1,46) = 1651, p less than .0001; self-care F(1,47) = 1062, p less than .0001; total F (1,47) = 1093, p less than .0001; no O/P therapy: mobility F(91,88) = 5643, p less than .0001; self-care F(1,88) = 5722, p less than .0001; total F(1,88) = 6733, p less than .0001. Pairwise comparisons for all functional indices revealed that all statistically significant changes in function in the no O/P therapy group occurred between stroke onset and discharge: self-care (p less than .0001), mobility (p less than .0001), and total (p less than .0001). Pairwise comparisons of all indices in the O/P therapy group revealed that all differences between stroke onset and discharge functional scores were at the p less than .0001 level, and score differences between discharge from inpatient rehabilitation and follow-up were as follows: self-care (p less than .05), mobility (p less than .001), and total (p less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Polysomnography in locked-in syndrome.

Sleep patterns were evaluated in a case of 'locked-in' syndrome. This patient had an ischemic infarction involving the ventral portion of the upper half of the pons bilaterally, with a posteromedial extension into the tegmentum. Reticular structures, notably the median raphe nuclei, supposed to play a major regulatory role in sleep, were most probably involved. Unexpectedly, repeated polysomnographic studies revealed sleep patterns with only minor abnormalities.

Stuttering as a manifestation of right-hemispheric subcortical stroke.

A right-handed man developed stuttering, without aphasia, as a result of a circumscribed subcortical infarction in the right hemisphere. He never stuttered before and has no family history of stuttering. Damage to callosal pathways coordinating the activity of both hemispheres during speech is proposed as a possible explanation for the stuttering.

Postural stability in stroke patients: vectorial expression of asymmetry, sway activity and relative sequence of reactive forces.

Bilateral force measurements on the supporting limbs in postural sway while standing still were made to evaluate post-cerebral-vascular accident (CVA) patients during rehabilitation. Normal subjects of the same age group were tested as controls. From the force tracings obtained, three oscillation frequencies were identified, with orders of magnitudes of 7, 1 and 0.1 Hz, respectively, of which the middle frequency, i.e. that corresponding to 1 Hz, was selected for subsequent processing and analysis. These included the determination of relative sequence of the force vectors on both feet and evaluation of timings and amplitudes of the waveforms. Weight-bearing imbalance was defined in the vertical direction to express the difference between the average forces supported by each of the legs. In the horizontal plane, two parameters were defined: sway total activity (SA), to represent the vector summation of the absolute values of the horizontal force components acting on both legs; and asymmetry (ASYM) to express the difference in activities between the two legs. The results presented disclose the reactive force patterns acting on each of the legs of post-CVA hemiplegic individuals, in comparison with normal individuals. Although these forces were shown to act synchronously on both legs, they appeared to be asymmetrical in nature, with a typical vectorial pattern for every individual, which generally differed from that of normal subjects. Sway activity was found to be significantly higher in hemiplegics compared with the normal controls.

Eye-sighting preference of normal and hemiplegic children and adults.

Monocular eye-sighting preference was examined in 32 children with hemiplegia, 51 adult-onset hemiplegic patients and 57 normal children and adults. Eye preference was compared with ear preference on dichotic listening for 25 of the hemiplegic children. No independent association could be detected between eye preference and ear preference. In both the children and adults with hemiplegia the preferred eye tended to be on the same side as the damaged hemisphere. Among the adults, this tendency was more pronounced with more extensive lesions, as manifested by aphasia and/or hemianopia. These findings are interpreted as indicating that eye-sighting preference is unrelated to unitary hemispheric dominance, and that, unlike dominance for hearing and speech, it is not irreversible after a critical period of development. A simpler explanation than incomplete hemispheric dominance is offered for the weakly positive association between mixed laterality and cerebral dysfunction.

Mutism associated with buccofacial apraxia and bihemispheric lesions.

Mutism following brain trauma is quite common, is usually transient, and recovery of speech is essentially the rule. Lasting total absence of speech without aphasia is highly unusual. Three such patients, two of traumatic and one due to vascular origin showing buccofacial apraxia (BFA) and computerized tomography (CT) evidence of bilateral frontal lesions are reported. It is suggested that complete lasting mutism associated with BFA is a result of bihemispheric lesions affecting mainly the opercular part of the inferior frontal gyrus and immediate adjacent regions.

Blink reflex in stroke: follow-up and correlation with function and CT parameters.

Blink reflex (BR) was examined serially in patients 1, 2 and 3 months after unilateral hemispheric cerebrovascular accident and compared with functional state and CT findings of lesion extent and location. BR R2 components were depressed and correlated with lesion size. Initial walking ability was correlated with latency and amplitude of both direct and consensual R2 elicited by stimulation of the paretic side. No correlation was found between BR and arm function or the final ambulatory ability. A model suggesting a close association between BR projection-facilitating fibers and those mediating facial movements is presented.