Brain-actuated functional electrical stimulation elicits lasting arm motor recovery after stroke

Brain-computer interfaces (BCI) are used in stroke rehabilitation to translate brain signals into intended movements of the paralyzed limb. However, the efficacy and mechanisms of BCI-based therapies remain unclear. Here we show that BCI coupled to functional electrical stimulation (FES) elicits significant, clinically relevant, and lasting motor recovery in chronic stroke survivors more effectively than sham FES. Such recovery is associated to quantitative signatures of functional neuroplasticity. BCI patients exhibit a significant functional recovery after the intervention, which remains 6-12 months after the end of therapy. Electroencephalography analysis pinpoints significant differences in favor of the BCI group, mainly consisting in an increase in functional connectivity between motor areas in the affected hemisphere. This increase is significantly correlated with functional improvement. Results illustrate how a BCI-FES therapy can drive significant functional recovery and purposeful plasticity thanks to contingent activation of body natural efferent and afferent pathways.

Influence of intrathecal baclofen on the level of consciousness and mental functions after extremely severe traumatic brain injury: brief report

BACKGROUND

Whenever oral treatment or botulinum toxin injections fail to control severe spasticity, a trial with intrathecal baclofen is recommended no earlier than 1 year after brain injury. When irreversible contractures are to be avoided, such a trial might be done earlier. Some have briefly reported cognitive modifications with this treatment.

METHODS

During the trial period, intrathecal baclofen is continuously infused by a portable external pump through an intrathecal catheter. The daily dose is adjusted according to the clinical response. If the expected response is obtained by reduction of spasticity, a programmable pump is then implanted. Throughout the procedure, close neuropsychological follow-up is pursued.

RESULTS

Two persons with extremely severe brain injury and spasticity received a programmable pump less than 10 months after trauma. Unexpectedly, one emerged from the minimally conscious state and the other from post-traumatic amnesia.

CONCLUSIONS

Intrathecal baclofen should be considered within the first year after brain injury whenever spasticity does not respond to medication. ITB lessens the degree of spasticity which in turn facilitates care and, thus, has the potential to limit contractures. After severe brain injury, this treatment might trigger recovery from altered states of consciousness, improve cognition and facilitate rehabilitation.

[Interest and costs of neurorehabilitation of brain injury patients]

The severity of the initial deficit and the improvement in the first weeks are the strongest indicators for a favorable outcome after stroke. Meta-analyses attempt to evaluate the efficacy of neurorehabilitation, but the results are unconclusive due to the heterogeinity of the groups of patients and therapies. However, there is sufficient data to conclude that repetitive, high intensity, task orientated training is efficacious. New approaches (mental imagery, robotics, virtual therapies...) are also useful but are not better than physiotherapy. It is as important to individualize the approach in a multidisciplinary well organised and communicative setting and to treat early complications. Cerebral plasticity is an individualized process and limited in time, so therapy should be regularly adapted and stopped if the deficit remains stable.

REPAS, a summary rating scale for resistance to passive movement: Item selection, reliability and validity

PURPOSE

To establish: (i) item characteristics and item selection for the REPAS; (ii) internal consistency, inter-rater and test-retest reliability of the final REPAS version and its subtests; (iii) the association between the REPAS and selected other clinical scales of impairment and activity limitation.

METHOD

Thirty-three neurological patients with central paresis. Two REPAS assessments with a one-week interval by two independent raters. Concurrent assessment of the Motricity Index, Box-and-Block test, Functional Ambulation Category, Timed walking, Barthel Index, Disability Rating Scale, Carer Burden Scale, and Hygiene Score.

RESULTS

Twenty-six of 52 REPAS items fulfilled the item selection criteria. The final test version showed a high internal consistency, inter-rater and test-retest reliability (correlation coefficients: 0.87-0.97, no significant difference between raters or with test repetition). Reliability of the arm and leg subtests was substantial (correlation coefficients: arm subtest 0.63-0.98, leg subtest 0.56-0.96). REPAS scores were moderately associated with basic ADL competence and a carer's burden with arm or leg adductor spasticity. The REPAS, arm subtest scores, degree of arm paresis and gross manual dexterity showed a moderately high association.

CONCLUSIONS

The Ashworth scale-based guidelines assured comparability of test administration and scoring. The REPAS is a reliable and valid summary rating scale for resistance to passive movement.

The effect of repetitive arm cycling on post stroke spasticity and motor control

This study's aims were (1) to test whether training on an arm ergometer improves motor performance, and (2) to develop a technique to quantify individual muscle spasticity. Nine patients with a stabilized hemisyndrome (in average 22 months after ischemic stroke in the territory of middle cerebral artery) underwent a 3-week training on an arm ergometer, 5 days/week. The patients were tested one week before training, at training onset, at the end of training and 2 weeks after training. Spasticity was quantified by (1) the Ashworth Scale of the elbow flexors and extensors, (2) the maximum active extension of the biceps, and (3) the minimum torque on the lesioned side during arm cycling. The data were standardized, pooled and a 2-way ANOVA revealed a decrease of the spasticity by the training (p=0.076). Similarly muscle force was evaluated by the Rivermead Motorik Assessment, the Motricity Index and the cycling force, and the range of active movement as the sum of the angles at a maximum shoulder flexion, shoulder abduction, elbow flexion and elbow extension. The training increased the force (p<0.01) and also the range of motion (p<0.05) significantly. The patients confirmed the clinical relevance of the results. The spasticity index - the relation between the muscle activity modulation on the normal and lesioned side - was shown to be a useful tool in quantifying individual muscle spasticity. It was concluded that cycling on an arm ergometer is a useful tool for rehabilitation.

Acute autonomic dysfunction contralateral to acute strokes: a prospective study of 100 consecutive cases

Complex painful reflex syndrome is sometimes described in the chronic phase of stroke. Acute autonomic dysfunction (AAD), which is occasionally present in cases of acute stroke, has not been studied prospectively. The aim of the study was to investigate AAD on the hemibody contralateral to the lesion in the acute phase of stroke. One hundred consecutive patients (median age +/- interquartile range, 74 +/- 21; range 19-93; 51 women: 80 +/- 17 and 49 men: 70 +/- 17 years) in the acute phase of stroke were studied prospectively. Changes in skin temperature or coloration, diaphoresis, pain, or edema were noted in the first 3 days post-stroke. Associations between AAD and topography (cortical pre- and/or post-central, insular, corona radiata, basal ganglia, internal capsule, thalamus, and brainstem), age, gender, ischemic or hemorrhagic etiology, or the presence of sensorimotor deficits or ataxia were examined using the chi-squared or Fisher's exact test and logistic regression analysis. AAD was found in 71% of the patients and showed a significant positive association with the presence of a lesion in the post-central cortex (P = 0.037), internal capsule (P = 0.005), basal ganglia (P = 0.002), or insula (P = 0.011) and a negative association with the presence of a lesion in the brainstem (P = 0.004). Multivariate logistic regression analysis including all studied topographic variables showed that only brainstem lesions were significantly associated with a decreased risk of developing AAD (odds ratio = 0.08, 95% confidence interval: 0.01-0.69, P = 0.022). AAD was not associated with age, gender, the ischemic or hemorrhagic nature of the lesion, the side of lesion, hypertonic or hypotonic paresis, or hyperreflexia or hyporeflexia. AAD was found in association with sensory deficits (P = 0.001) and contralateral hyperkinesia (P = 0.004). Acute AAD is significantly more likely to occur in the presence of hemispheric lesions involving sensory pathways from the cortex to the internal capsule and insula and is significantly less prevalent in the presence of brainstem lesions.

Clinical scales for the assessment of spasticity, associated phenomena, and function: a systematic review of the literature

PURPOSE

To characterise clinical assessment methods for spasticity and/or its functional consequences in clinical patient populations at risk to suffer from spasticity.

METHOD

Systematic literature search and manual-based two-step review process of psychometric properties of clinical assessment scales for spasticity and associated phenomena, as well as of functional scales with an association with spasticity. Reviewed psychometric properties included internal consistency, interrater, intrarater as well as retest reliability, construct validity, ecological validity, and responsiveness.

RESULTS

Until May 2003 electronic database searches established a reference pool of 4151 references of which 90 references contributed to the review objectives. An additional 20 references were identified by an informal reference search. Twenty-four clinical scales that assess spasticity and/or related phenomena as well as 10 scales for 'active function' and three scales for 'passive function' with an association with spasticity could be identified. Some evidence signals that a high interrater reliability of the Ashworth and modified Ashworth scales can be achieved, however not in all circumstances. For many scales, reliability data is, however, missing. This is especially true for test retest reliability. Information about construct validity can promote our understanding of what individual scales are likely to assess. Many scales have been able to document changes after therapeutic intervention.

CONCLUSIONS

The collated evidence can guide our clinical decision about when to use which scale and can promote evidence-based assessment of spasticity and related clinical phenomena.

[Functional assessment of the hand in neurologic rehabilitation]

Functional evaluation of hand is essential in neurorehabilitation because it provides crucial information about capacities/incapacities of patients during their daily activities. Then therapists can plan realistic aims. This evaluation is usually devoted to occupational therapists, who have different tests and scales to measure the functions of hand. The movements and gestures of hands are so various and complex that no test is better than another. Here we select a few specific tests to evaluate hand functions and we present their advantages and interest in neurorehabilitation.

[Assessment of car driving skills in brain injured individuals]

Independent driving is considered as very important for a full independence and social integration of disabled people. In these patient with disabilities or handicaps, the driving skills must be carefully assessed, especially in presence of a moderate dysexecutive syndrome. A precise neurological and neuropsychological examination is usually necessary to evaluate aptitudes for driving. Standard neuropsychological tests are often limited to value the brain injury patients. At the moment, assessment on driving simulators really improves the opinion of medical experts, as they give qualitative and quantitative data on reproducible conditions. In fact, in more than 80% of cases, the tests on driving simulators allow to determine if the patient is able to drive or no, with or without a specially adapted vehicle. However, in a small percentage of cases, the evaluation of open-road driving by a driving instructor is necessary, proving that driving simulators will never take over from reality.

[Role of drugs in recovery from brain damage]

The mechanisms that enhance recovery from brain lesion are more and more precise. The role of neurotransmitters and post-synaptic receptors are essential. Different drugs acting at the level of synapses are potentially useful but still few used in neurorehabilitation. The aim of this article is to review the drugs that can be prescribed in selected situation. In spite of encouraging results of numerous studies, a lot of questions remain and prove the need of large randomised studies to determine the real benefit of drugs in rehabilitation. Moreover, if the activation of neurotransmitters can improve recovery, all their antagonists will produce the inverse effect. Therefore, the choice of drugs in neurorehabilitation is essential.

[Cerebral venous thrombosis after lumbar puncture and intravenous steroids in two patients with multiple sclerosis]

Two patients affected with a multiple sclerosis developed cerebral venous thrombosis after lumbar puncture and treatment with intravenous methylprednisolone. In one case, the course was favorable. The second patient died in spite of intracerebral thrombolysis. The autopsy confirmed the diagnosis of cerebral venous thrombosis and multiple sclerosis. We discuss the relationship between lumbar puncture, steroid treatment and cerebral venous thrombosis.

Impact of cerebrospinal fluid PCR on the management of HIV-infected patients with varicella-zoster virus infection of the central nervous system

Over a 2 year period, we identified five HIV-infected patients who presented with central nervous system infection caused by varicella-zoster virus, three with myelitits, and two with meningoencephalitis. All five patients were profoundly immunocompromised. Clinical presentation of these patients overlapped to a significant extent with diseases caused by other viruses, e.g. CMV. Indeed, in one case, a dual infection with CMV was diagnosed, but the respective role of each virus was ascertained by in situ hybridisation. At the time of CNS involvement, only one patient had active VZV cutaneous lesions, which were instrumental in diagnosing her condition. In contrast, PCR for VZV DNA in the CSF was helpful in making a diagnosis in the four other cases, one of which was confirmed by a post mortem. Of these five patients, two patients developed VZV disease while receiving oral acyclovir and had foscarnet treatment initiated when MRI demonstrated widespread lesions. They did not respond to antiviral therapy. The three other patients had intravenous acyclovir initiated at a time when no or limited parenchymal lesions were observed by MRI. Two of these three patients had VZV infection diagnosed solely on the basis of PCR: all three responded to treatment. Our data show that reactivation of VZV involving the central nervous system occurs frequently in the absence of cutaneous lesions. PCR of cerebrospinal fluid may help in making an early diagnosis which is probably a prerequisite for successful treatment of VZV infection of the CNS.

Autologous fat injection for soft tissue augmentation in the face: a safe procedure?

Autologous fat injection for soft tissue augmentation in the face is claimed to be a safe procedure. However, there are several case reports in the literature where patients have suffered from acute visual loss and cerebral infarction following fat injections into the face. Acute visual loss after injection of various substances into the face is a well-known complication of such interventions. We report two further patients who suffered from ocular and cerebral embolism after fat injections into the face. For the intravasation of fat particles there are three preconditions: well-vascularized tissue, fragmentation of parenchyma, and, especially, a local increase in pressure in the affected tissue. Fat injections into the face lead to an acute local increase in pressure in highly vascularized tissue. We assume that fragments of fatty tissue reach ocular and cerebral arteries by reversed flow through branches of the carotid arteries after they are introduced into facial vessels. The manifestation of fat embolism appears either immediately after the fat injection or after a latency period. Fat embolism can remain subclinical and may not be recognized, or the clinical features may be misinterpreted. To minimize the risk of such a major complication, fat injections should be performed slowly, with the lowest possible force. One should avoid fat injections into pretraumatized soft tissue, for example, after rhytidectomy, because the risk of intravasation of fat particles may be higher. Metabolic disturbances such as hyperlipidemia may also contribute to the clinical manifestation of fat embolism Routine funduscopic examinations after fat injections into the face could help to provide data for future estimation of the patient's general risk.

Bihippocampal damage with emotional dysfunction: impaired auditory recognition of fear

A right-handed man developed a sudden transient, amnestic syndrome associated with bilateral hemorrhage of the hippocampi, probably due to Urbach-Wiethe disease. In the 3rd month, despite significant hippocampal structural damage on imaging, only a milder degree of retrograde and anterograde amnesia persisted on detailed neuropsychological examination. On systematic testing of recognition of facial and vocal expression of emotion, we found an impairment of the vocal perception of fear, but not that of other emotions, such as joy, sadness and anger. Such selective impairment of fear perception was not present in the recognition of facial expression of emotion. Thus emotional perception varies according to the different aspects of emotions and the different modality of presentation (faces versus voices). This is consistent with the idea that there may be multiple emotion systems. The study of emotional perception in this unique case of bilateral involvement of hippocampus suggests that this structure may play a critical role in the recognition of fear in vocal expression, possibly dissociated from that of other emotions and from that of fear in facial expression. In regard of recent data suggesting that the amygdala is playing a role in the recognition of fear in the auditory as well as in the visual modality this could suggest that the hippocampus may be part of the auditory pathway of fear recognition.

[Behavior disorders of neurological origin]

The modifications of behavior related to neurological diseases are various and important to be correctly diagnosed. The purpose of this article is to present the clinical features of main neuropsychiatric syndromes: depression, delusions, anxiety, obsessive-compulsive syndrome. The differential diagnosis is also developed. The appropriate treatment is discussed.

[Olivo-ponto-cerebellous degeneration. A study of 21 patients defined by the Quinn criteria]

21 patients with diagnosis of idiopathic OPCA were examined clinically and evaluated by MRI or CT-scan. On the basis of Quinn's criteria for MSA, patients were subdivided into those with probable MSA (48 p. cent) and those with possible MSA (52 p. cent). Median age at onset was 51.8 years. The initial clinical feature of the disease was ataxia, but the presence of multiple system involvement was clear in all cases. The combination of involvement of four different system (cerebellar, parkinsonian, pyramidal, autonomic) was the most common (28.5 p. cent), followed by the association of cerebellar and pyramidal features (24 p. cent). Autonomic symptoms were present in 48 p. cent of patients. CY-scan or MRI showed cerebellar and brainstem atrophy in 43 p. cent of cases. There was no relation with the duration of the disease or the severity of clinical features. Moreover brainstem auditory evoked response and EMG were not helpful in diagnosis.

Visual disturbances and transurethral resection of the prostate: the TURP syndrome

A 73-year-old man with a history of a cerebral and a cardiac vascular disease and atrial flutter developed visual disturbances characterized by vision being dark in both eyes and by seeing as through a color photographic negative immediately after an uncomplicated transurethral resection of the prostate (TURP) for prostatic hyperplasia under spinal anesthesia. There was complete remission of the symptomatology after 2.5 h. A cerebrovascular workup was negative. Considering postoperative hyponatremia and hypoosmality, we discuss the possible role of glycine-induced visual disturbances as described in the TURP reaction syndrome, to our knowledge an entity almost unknown in the neurologic literature. Glycine-induced visual disturbances should therefore be considered in the differential diagnosis of bilateral transient visual loss.

Justification of hospital days and discharge delays in a non-selected population of acute stroke patients

Using a published protocol, we evaluated a non-selected population of stroke patients to identify unnecessary days of hospitalisation in the Department of Neurology at the Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. This study was undertaken to determine whether physicians can modify the non-medically justified hospital days. We prospectively studied 118 patients with stroke admitted to our Department over a period of 5 months. Each day spent on the ward was placed in one of two categories: those due to medical reasons (1,391 hospital days) and those due to non-medical reason (518 days). Using a previously published protocol, 74 parameters were evaluated. Delays in obtaining examinations or a specialist's consultation accounted for a small proportion of waiting days (1.9% of total hospital days), which was greater in patients who were not disabled (0.9% of hospital days) than in patients with total dependence (0.2% of hospital days). The delays resulted mainly from awaiting transfer either to another department or to a nursing home. The length of stay increased with severity of dependence. However, the number of days spent for transfer to a nursing home was also relatively high in the non-dependent patient group (42% of hospital days). This study demonstrates that neurologists cannot easily influence the length of stay in hospital. It also corroborates the need to develop short- and long-term chronic care facilities to facilitate the transfer of patients once there are no further medical reasons for staying in hospital.

[Preventive treatment of cerebrovascular accidents of arterial origin]

Inhibitors of platelet aggregation are in use for prevention of cerebrovascular insults (CVI). Aspirin at a dose of 250 +/- 100 mg/day is the most common regimen for patients at an elevated risk for vascular complications. Aspirin and ticlopidine (500 mg/day) are the best drugs for secondary prevention of arterio-arterial cerebrovascular incidents. Efficacy of inhibitors of platelet aggregation in prevention of primary cerebral infarcts has not been demonstrated. An analogue of ticlopidine, clopidogrel is presently under comparison with aspirin in the prevention of CVI. Endarterectomy of the carotid has been evaluated in several studies for prevention of CVI. In patients with symptomatic carotid stenosis (70 to 99%), endarterectomy decreases the risk for cerebral infarcts by 20 to 44%. The indication for endarterectomy in patients with asymptomatic stenosis has to be posed reluctantly because of controversial interpretations of recent study results.

[Drug-induced neurological complications in a hospital cohort]

Among the patients admitted to our clinic between 1988-1994, we selected 109 with a neurologic disorder induced by medication. We registered 34 cases of drug-induced headache, 33 of extrapyramidal syndrome, 10 of polyneuropathy, and 5 of myopathy. 12 patients presented neurologic side effects of antiepileptic drugs, and 15 were admitted for epileptic seizures or neuropsychological alterations induced by drugs. The purpose of this article is to review the clinical symptoms of these types of neurologic disorders. It also discusses the drug-induced neurologic complications encountered in general practice. Therapeutic advice, and particularly the choice of psychotropic drugs for epileptic or elderly patients, is proposed.

[Eosinophil meningoradiculitis caused by Angiostrongylus cantonensis]

The authors report the case of a 46-year-old woman who presented with an eosinophilic meningoradiculits after a trip to Tahiti. Because of the type of presentation of the symptomatology, the CSF findings, and the spontaneously favourable outcome, it was related to an infection by Angiostrongylus cantonensis. The authors review the neurological manifestations of this parasite and emphasize the different clinical aspects of infection by Gnathostoma spinigerum, which causes myeloencephalitis in the South-East of Asia.