Acute subcortical stroke and early serotonergic modification: a IDAP study

The intensity dependence of the auditory-evoked potentials (IDAP) is inversely related to serotonergic tone. Depression is frequently observed after stroke, associated with cognitive impairment and increased mortality. Aim of this study was to investigate the serotonergic tone in acute stroke patients by IDAP. Consecutive patients with an acute stroke admitted in our stroke unit were evaluated using clinical and instrumental examinations and compared with healthy controls. The IDAP was calculated as the linear amplitude/stimulus intensity function (ASF) slope, by measuring the peak-to-peak amplitude of Nl-P2 on four blocks of different stimulus intensities. Twenty patients were enrolled; 11 had a right brain infarction; nine had depressive symptoms (DS). The ASF slope of the auditory-evoked potentials was markedly increased in stroke patients compared with controls ( P  = 0.021). Stroke patients with DS had a significant steeper ASF slope than controls ( P  = 0.017). There was no statistical difference in ASF slope between stroke patients without DS and controls. Post-stroke depression pathophysiology is still debated. Our study suggests that in acute stroke patients with DS, there is a direct involvement of the serotonergic system, regardless the degree of disability and the site of the lesion.     

Mechanisms of early and late recovery in acute motor axonal neuropathy

Motor unit number estimate (MUNE) of the abductor pollicis brevis (APB) was sequentially performed in seven patients with acute motor axonal neuropathy (AMAN). The MUNE markedly decreased (mean, 11) at the peak of the illness. Clinical recovery of APB strength began during week 4, with an increase in amplitude of distal compound muscle action potentials. The MUNE did not change significantly in this early recovery phase and increased slowly with time. The main mechanism for early recovery in AMAN may be collateral reinnervation, with nerve regeneration developing later.     

Magnetic resonance imaging in multiple sclerosis: investigation of brain and spinal cord lesions

Magnetic resonance imaging (MRI) of the brain was performed on forty-five patients with multiple sclerosis (MS), using T1-weighted inversion recovery and T2-weighted spin echo images, and the results were compared with X-ray computed tomography (CT). Some of the 45 MS patients were also examined by neurophysiological studies (visual evoked potentials and auditory brainstem responses) to compare with the brain MRI findings. MRI showed demyelinating plaques of the brain in 20 (74%) of 27 patients with brain symptoms, 11 (61%) of 18 patients without symptoms and 31 (69%) of all 45 patients. In 27 patients with brain symptoms, MRI was able to detect brain lesions in 6 (86%) of 7 acute stage patients and 14 (70%) of 20 non-acute stage patients. Furthermore, MRI was able to detect brain lesions in 21 (70%) of 30 clinically definite MS patients and 10 (67%) of 15 clinically probable MS patients. X-ray CT was performed on all 45 patients and was able to detect brain lesions in 9 (33%) of 27 patients with brain symptoms and 1 (6%) of 18 patients without symptoms. Visual evoked potentials were evaluated in 31 patients, and showed abnormalities in 1 (11%) of 9 patients without symptoms of optic neuritis and 100% of 22 patients with symptoms. Auditory brainstem responses were evaluated in 19 patients, and showed abnormalities in 1 (11%) of 9 patients without brainstem symptoms and 3 (30%) of 10 patients with symptoms. MRI of the brain was markedly superior to X-ray CT, visual evoked potentials and auditory brainstem responses in detecting clinically unsuspected lesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Awaji ALS criteria increase the diagnostic sensitivity in patients with bulbar onset

ObjectiveTo assess whether Awaji criteria improve the sensitivity of diagnosis for amyotrophic lateral sclerosis (ALS). In Awaji ALS criteria, fasciculation potentials are regarded as evidence of acute denervation in the presence of chronic neurogenic changes on needle electromyography.MethodsWe reviewed clinical and neurophysiological data of 113 consecutive patients who were suspected as suffering ALS. The six muscles (trapezius, biceps, first dorsal interosseous, T10-paraspinalis, vastus lateralis, and tibialis anterior muscles) were examined by EMG, focusing on the presence of fasciculation potentials. The sensitivity of revised El Escorial (R-EEC) and Awaji criteria was compared.ResultsProbable or definite ALS was diagnosed in 61% of the patients by R-EEC and 71% by Awaji criteria. By applying Awaji criteria; (1) 17 of the 44 patients categorized as possible ALS by R-EEC reached to probable/definite ALS, 11 of whom had bulbar onset, (2) in 48 patients with bulbar onset, the proportion of probable/definite ALS increased from 59% to 82%, (3) in 62 patients with limb onset, the proportion of probable/definite ALS was 61% (63% by R-EEC).ConclusionsAwaji criteria improve the sensitivity of ALS diagnosis in patients with bulbar onset, but not in those with limb onset.SignificanceAccepting fasciculation potentials as evidence of acute denervation increases the diagnostic sensitivity of ALS, particularly in patients with bulbar onset, and contributes to early diagnosis.     

Acute exacerbation of multiple sclerosis increases plasma levels of S-100 protein

Objectives - To determine whether an increase in plasma concentration of S-100 protein can serve as a marker for acute exacerbation of multiple sclerosis. Material and methods - The plasma level of S-100 protein was investigated in 28 patients suffering from multiple sclerosis. Of these, 17 patients were admitted for acute exacerbation and 11 patients had a stable disease with no clinical signs for acute exacerbation. S-100 protein concentrations in plasma were determined with an immunofluorometric sandwich assay. Results - Plasma concentrations were significantly elevated in patients who were examined within 7 days after the onset of acute exacerbation ( n =6). S-100 levels of patients 8 to 28 days after the onset of acute exacerbation ( n =11) did not differ from healthy controls ( n =120). Eleven patients with multiple sclerosis without acute exacerbation had moderately elevated plasma levels. Conclusion - The plasma concentration of S-100 protein is a sensitive although unspecific indicator of neuronal damage and may be of use as a marker of disease activity in multiple sclerosis.     

Serotonin 5HT1A receptor availability and pathological crying after stroke

OBJECTIVES: Post-stroke depression and pathological crying (PC) implicate an imbalance of serotonergic neurotransmission. We claim that PC follows serotonin depletion that raises the binding potential (p(B)) of the 5-HT(1A) receptor antagonist [carbonyl-(11)C]WAY-100635, which is reversible by selective serotonin re-uptake inhibitor (SSRI) treatment. MATERIALS AND METHODS: We PET scanned patients with acute stroke and PC and age-matched control subjects. Maps of receptor availability were generated from the images of eight cortical regions and raphe nuclei. RESULTS: The maps showed highest binding in limbic areas and raphe nuclei, while binding in basal ganglia and cerebellum was negligible. Baseline binding potentials of patients were lower than that of control subjects (3.7 +/- 0.6 vs 4.2 +/- 0.2). Treatment with SSRI markedly reduced free receptor sites, whereas placebo administration led to a global increase. DISCUSSION: The study is the first suggestion of changes of serotonergic neurotransmission in the early phase of stroke and the modulation of these changes with SSRI treatment.     

Schizophrenia, psychoticism, neuroleptics, and auditory evoked potentials

Auditory cortical evoked potentials of 20 schizophrenic patients with an acute exacerbation of the illness were investigated before neuroleptic medication and after remission of the acute symptoms, and compared with healthy controls matched for sex and age. Additionally, tests were conducted in 40 healthy volunteers to ascertain whether psychoticism or other personality factors were correlated with evoked potentials. The aim of the study was to test the overarousal hypothesis of schizophrenia and to control the effects of clinical state, neuroleptic medication and personality factors. Acutely ill schizophrenic patients had a shorter evoked potential N1 latency (Table 1). After remission of the symptoms under haloperidol N1 latency of the patients was no longer different from that of the controls. Patients after remission and on medication, however, had longer P2 and N2 latencies and a greater P2-N2 amplitude (Table 2). Psychoticism and extraversion were correlated negatively with amplitude data of components N1 and P2 in healthy volunteers. The results favor the overarousal hypothesis of schizophrenia. Haloperidol normalizes N1 latency in acutely ill patients. It's effect on later components of the evoked potentials seems comparable to a reduction in vigilance. Auditory evoked potentials might allow to follow up the effect of neuroleptics in acute schizophrenia. It seems necessary to consider personality factors when comparing patients with healthy controls in evoked potential studies.     

Spinal arteriovenous malformations: Clinical and neurophysiological findings

Eighteen patients with dural arteriovenous fistulas or intradural arteriovenous malformations underwent clinical and neurophysiological examination. Bladder disturbances, pain, sensory abnormalities and involvement of both upper and lower motor neurons were commonly observed. Abnormal findings were obtained both in electromyography (11/18) and somatosensory evoked potentials (16/18). The motor evoked potentials were abnormal in all but one patient and showed a prolonged central (n = 14) or peripheral motor conduction time (n = 6). In three cases both values were prolonged. The results of nerve conduction studies in the patients with prolonged peripheral motor conduction times were normal. These neurophysiological findings may indicate root involvement in some patients, probably due to venous congestion and consequent hypoxia, as there were no signs of root compression on neuroradiological evaluation in any of these six patients. Motor evoked potentials may provide an additional clue to the diagnosis, although patients with spinal stenosis or motor neuron disease may present with similar findings.     

Abnormalities of multimodality evoked potentials in amyotrophic lateral sclerosis

Thirty-two patients with amyotrophic lateral sclerosis were studied with somatosensory evoked potentials (SEPs), visual evoked potentials, and brain-stem auditory evoked potentials. H-reflexes were used to screen for abnormalities of peripheral nerve conduction. Nineteen patients (59%) showed an abnormality of lower extremity SEPs. In 13 patients (40%) the delay was of central origin, while in six patients (19%) peripheral conduction delay was possible. Abnormality of upper limb SEPs was seen in 11 patients (34%), all but two of whom had abnormal lower limb SEPs as well. Four patients (12%) had abnormal brain-stem auditory evoked potentials, all of whom had abnormal SEPs from upper and lower limbs. Four patients had abnormal visual evoked potentials, which in three patients were of minor degree. These results give physiologic evidence to suggest that abnormalities in amyotrophic lateral sclerosis occur outside the motor system.     

脑卒中患者急性期脑电生理变化与CT成像的临床研究

目的 探讨急性缺血性脑卒中患者脑电生理变化和CT成像的临床意义. 方法 对56例发病后即刻入院的缺血性脑卒中患者检测的CT、脑电图(EEG)、脑电地形图(BEAM)、体感诱发电位(SEP)、经颅磁刺激运动诱发电位(MEP)和神经功能缺损评分(MESSS)及日常生活能力评分(BI)情况进行对比研究及相关分析. 结果 EEG局限性异常与CT显示病变位置基本一致,但病灶范围存在一定差异.自身患/健侧SEP和MEP比较差异有统计学意义(P<0.05).入院不同时间MESSS与入院第28天BI值分析显示两者呈正相关(r=0.58,P<0.05).结论 CT成像与脑电生理检查在缺血性脑卒中急性期具有较高的早期诊断价值.     

X-linked spinal and bulbar muscular atrophy (Kennedy's disease) with long-term electrophysiological evaluation: case report

X-linked spinal and bulbar muscular atrophy or Kennedy's disease is an adult-onset motor neuronopathy caused by a CAG repeat expansion within the first exon of an androgen receptor gene. We report the case of a 66-year-old man, previously diagnosed with motor neuron disease (MND), who presented acute and reversible left vocal fold (dysphonia) and pharyngeal paresis, followed by a slowly progressive weakness and also bouts of weakness, wasting and fasciculation on tongue, masseter, face, pharyngeal, and some proximal more than distal upper limb muscles, associated to bilateral hand tremor and mild gynecomastia. There were 5 electroneuromyography exams between 1989 and 2003 that revealed chronic reinnervation, some fasciculations (less than clinically observed) and rare fibrillation potentials, and slowly progressive sensory nerve action potentials (SNAP) abnormality, leading to absent/low amplitude potentials. PCR techniques of DNA analysis showed an abnormal number of CAG repeats, found to be 44 (normal 11-34). Our case revealed an acute and asymmetric clinical presentation related to bulbar motoneurons; low amplitude/absent SNAP with mild asymmetry; a sub-clinical or subtle involvement of proximal/distal muscles of both upper and lower limbs; and a probable evolution with bouts of acute dennervation, followed by an efficient reinnervation.     

Evoked potentials in multiple sclerosis before and after high-dose methylprednisolone infusion

We studied 8 patients with definite multiple sclerosis (3 with acute relapse, 5 with progression), and 2 patients with acute optic neuritis, who were treated with methylprednisolone infusions, 1 g daily for 3 days. Visual, brain stem-auditory and somatosensory-evoked potentials were used to test the effect of therapy. There were no manifest changes of the evoked potentials parameters parallel to the clinical effect of high-dose therapy.     

Cerebral evoked potentials in multiple sclerosis

Multimodal evoked potentials were analyzed from 58 possible, 62 probable and 100 definite (total 220) multiple sclerosis (MS) patients. Visual evoked potentials (VEP) were most frequently abnormal yielding 39%, 69%, 84% in the three diagnostic groups respectively. Median nerve sensory evoked potentials (SEP) yielded abnormalities in 26%, 65%, 79% respectively. Brainstem auditory evoked responses (BAER) were abnormal in 17%, 39%, 66% respectively. We measured the combined amplitude (CA) of waves III, IV, V in the BAER of these patients as an objective measure of amplitude asymmetry. The CA was considered abnormal if it was 1SD below the lowest CA value in the control group. The CA was abnormal in 9.2% of BAER with normal central conduction time. The BAER diagnostic yield in MS patients increased 11% by using CA analysis.     

Lumbosacral evoked potentials and vesicourethral function in patients with chronic suprasacral spinal cord injury.

Persistent detrusor acontractility despite normal somatic reflex activity in some patients with high spinal cord injury is an enigma. Previous work has suggested disordered integration of afferent activity in sacral roots or the sacral spinal cord. Forty male patients with chronic stable suprasacral cord lesions were studied by filling and voiding videocystometrography, and recording lumbosacral evoked potentials from posterior tibial nerve stimulation. Only five of 15 patients with decreased detrusor contractility had abnormal lumbosacral evoked potentials. Similar abnormalities were found in four of 11 patients with efficient hyperreflexic bladders. The finding of normal lumbosacral evoked potentials in the majority of patients with suprasacral cord injuries and decreased detrusor contractility supports the argument that the pathophysiology of this specific form of neurogenic bladder dysfunction is multifactorial.     

P300 subcomponent abnormalities in schizophrenia: III. Deficits In unaffected siblings of schizophrenic probands.

BACKGROUND: Reduced P300 amplitude is a robust finding in patients with schizophrenia. In previous investigations, we reported reductions of specific subcomponents of the auditory oddball P300 that were independent of acute symptomatology and persistent over time, consistent with a trait abnormality. To clarify whether these stable deficits represented genetic markers of vulnerability to schizophrenia, event-related brain potentials (ERPs) from patients were compared to those from their own healthy siblings and unrelated control subjects. METHODS: Auditory P300 ERPs were acquired from 11 schizophrenic patients, 12 healthy siblings and 23 matched control subjects. Five P300 subcomponents were identified using current source density measures: frontal, bilateral parietal, and bilateral temporal. RESULTS: Consistent with previous reports, patients had reduced parietal and frontal P300 amplitudes. The healthy siblings of the schizophrenic probands had an isolated reduction of the frontal P300. CONCLUSIONS: Frontal P300 amplitude is a potential endophenotypic marker of genetic vulnerability to schizophrenia in individuals who otherwise show no evidence of clinical symptomatology. Given the functional interpretation of the frontal P300 as a physiological correlate of cognitive orienting, this supports the hypothesis that impairments of the neural substrate underlying attentional mechanisms are selective indicators of genetic susceptibility to schizophrenia in high-risk individuals.     

Bladder dysfunction in acute transverse myelitis: magnetic resonance imaging and neurophysiological and urodynamic correlations

AIMS: To evaluate micturition abnormalities in acute transverse myelitis and correlate these with evoked potentials, magnetic resonance imaging (MRI), and urodynamic findings. SETTING: Tertiary care teaching hospital. PATIENTS: 18 patients with acute transverse myelitis, aged 4-50 years; 15 had paraparesis and three quadriparesis. METHODS: Patients with acute transverse myelitis had a neurological evaluation and tibial somatosensory and motor evoked potential studies in the lower limbs. Spinal MRI was carried out using a 1.5 T scanner. Urodynamic studies were done using Dantec UD 5500 equipment. Neurological outcome was determined on the basis of Barthel index score at six months as poor, partial, or complete. In some patients, urodynamic studies were repeated at six and 12 months. RESULTS: Spinal MRI in 14 of the 18 patients revealed T2 hyperintense signal changes extending for at least three spinal segments in 13; one patient had normal MRI. In the acute stage, 17 patients had a history of urinary retention and one had urge incontinence. On follow up at six months two patients regained normal voiding, retention persisted in six, and storage symptoms developed in 10, of whom five also had emptying difficulties. Urodynamic studies showed an areflexic or hypocontractile bladder in 10, detrusor hyperreflexia with poor compliance in two, and detrusor sphincter dyssynergia in three. Early abnormal urodynamic findings commonly persisted at the six and 12 months examinations. Persistent abnormalities included detrusor hyperreflexia, dyssynergia, and areflexic bladder. The urodynamic abnormalities correlated with muscle tone and reflex changes but not with sensory or motor evoked potentials, muscle power, MRI signal changes, sensory level, or six months outcome. CONCLUSIONS: Bladder dysfunction is common in acute transverse myelitis and may be the only sequel. Urodynamic study is helpful in evaluating the bladder dysfunction and also in its management.     

Evoked potentials in neonates and infants with aseptic meningitis

We investigated 4 infants with aseptic meningitis, 4–38 days of age, by repeated electroencephalography (EEG), flash-visual evoked potentials (F-VEPs), and brainstem auditory evoked potentials. The patients all had mild, acute phases and favorable outcomes at 1–2 years of age. EEGs and F-VEPs obtained within 1 month after onset all were defined as abnormal. In 3 patients, EEG findings were normal 1–2 months after onset, while F-VEP findings were normal at 9–10 months. Brainstem auditory evoked potential findings were normal, except for 1 with otitis media. Evoked potentials suggested that subclinical brain damage, especially due to cortical lesions, persisted during the first year of life in these patients clinically diagnosed with “meningitis.”     

Functional prognosis in stroke: use of somatosensory evoked potentials.

Median nerve somatosensory evoked potentials (SEPs) were performed on 35 patients with acute stroke and correlated with functional outcome as measured by placement, length of stay and an activities of daily living index (Barthel Index). There was a statistically significant correlation of both SEP and sensory examination at the 0.05 level to eventual functional outcome. SEPs were better than age, sex and side of CVA in predicting functional outcome as measured by these scores. SEPs and sensory examination are interrelated but SEPs offer the advantages of objectivity, the ability to quantify results and the use in unconscious or dysphasic patients.     

Multimodal evoked potentials in progressive external ophthalmoplegia with mitochondrial myopathy

Multimodal evoked potentials were studied in 13 patients affected by progressive external ophthalmoplegia with histologically proven mitochondrial myopathy. Progressive external ophthalmoplegia occurred with craniosomatic spreading in all the patients and with a varying degree of nervous and/or other system involvement in most of them. In all but one of the subjects, at least one evoked potential modality was abnormal; 11 of them demonstrated an abnormal visual evoked potential, but this finding might have been influenced by concurrent retinal dysfunction. Abnormalities in brainstem auditory evoked potentials and/or somatosensory evoked potentials, revealing an impairment of central sensory pathways, were detected in 7 subjects, 5 of whom lacked clinical evidence of central nervous system involvement. Thus, evoked potentials represent an useful tool for the detection of subclinical central nervous system involvement in patients affected by progressive external ophthalmoplegia with mitochondrial myopathy.     

Predicting outcome in hypoxic-ischemic coma. A prospective clinical and electrophysiologic study.

A prospective analysis of 40 patients with hypoxic-ischemic coma lasting at least 6 h following sudden cardiac arrest was undertaken. The patients, all of whom had preserved brain-stem function, were studied electrophysiologically with electroencephalography (EEG), and median nerve somatosensory evoked potentials (SEPs) within 48 h to establish prognostic indices. Our results indicate that preserved brain-stem function does not necessarily predict favorable outcome following cardiac arrest as 26 of 40 (65%) patients died without awakening. The bilateral absence of cortical evoked potentials predicted death without awakening in 19 of 26 patients (73%) while malignant EEG change was similarly predictive in 11 patients (42%). Bilateral absence of cortical evoked potentials and/or malignant EEG change reliably predicted unfavorable outcome in 21/26 patients (81%). Patients with normal or delayed central conduction time (CCT) as well as 'benign' or 'uncertain' EEG findings had an uncertain prognosis as some entered a persistent vegetative state (PVS) or died without awakening. Fourteen patients (35%) awakened of whom 5 (13%) recovered completely while another 9 (23%) had varying degrees of motor or cognitive impairment. SEP and EEG findings did not distinguish between these outcomes.