Neurophysiological patterns of acute and post-acute foodborne botulism.

INTRODUCTION/AIMS: Neurophysiological patterns in patients with foodborne botulism are rarely described after the acute phase. We report data from a large Italian outbreak of botulism, with patients evaluated at different timepoints after poisoning. METHODS: Eighteen male patients (mean age 47 ± 8.4 y) underwent 22 clinical and neurophysiological evaluations (4 patients were re-evaluated). The resting compound muscle action potential (CMAP) amplitude, postexercise CMAP amplitude, CMAP change after high-frequency (50 Hz) repetitive nerve stimulation (HFRNS), and motor unit action potentials (MUAPs) were assessed in the acute (4-8 days after poisoning; 5 patients), early post-acute (32-39 days after poisoning; 5 patients), and late post-acute (66-80 days after poisoning; 12 patients) phases. RESULTS: In the acute, early post-acute, and late post-acute phases, respectively, reduced CMAP amplitudes were found in 100%, 20%, and 17% of patients; abnormal postexercise CMAP facilitation was observed in 100%, 40%, and 0% of patients; and pathological incremental responses to HFRNS were found in 80%, 50%, and 8% of patients. Baseline CMAP amplitudes, postexercise CMAP facilitation, and CMAP increases in response to HFRNS differed significantly between the acute and post-acute phases. Small MUAPs were found in 100% of patients in the acute and early post-acute phases and in 50% of patients in the late post-acute phase. DISCUSSION: The neurophysiological findings of foodborne botulism vary considerably according to the evaluation time point. In the post-acute phase, different neurophysiological techniques must be applied to support a diagnosis of botulism.

A commercially available device suppresses photic driving: implications for EEG recording.

Intermittent photic stimulation (IPS) is an activation procedure routinely performed during EEG. The EEG response may consist in physiological photic driving (PPD) or in photoparoxysmal response (PPR). Sometimes, the distinction between PPR and PPD can be challenging, especially in case of PPR limited to posterior regions (Waltz type 1 or 2). A commercially available device, namely Zeiss Clarlet F133 lenses (ZEISS lenses), can suppress PPR, while its influence on PPD is still unknown. This study aims to test the effect of ZEISS lenses on PPD at different flash frequencies. We prospectively collected all consecutive EEGs showing PPD to IPS, performed both with eyes open and closed at stimulation frequencies between 3 and 24 Hz. When PPD was present, IPS with ZEISS lenses was performed. We analyzed the presence of PPD without and with lenses by means of McNemar's test We included 97 EEGs showing PPD. This response was more commonly obtained at flash frequencies between 6 and 12 Hz. The use of ZEISS lenses significantly decreased the proportion of subjects showing PPD at each frequency (p < 0.001 for all comparisons). ZEISS lenses significantly reduce the proportion of subjects showing PPD at all stimulus frequencies, regardless of eye opening or closure. Physicians should consider that ZEISS lenses do not allow distinction between PPD and PPR. The effect of ZEISS lenses on PPR and on PPD suppression suggests that these two phenomena derive from similar mechanisms involving the entrainment of neural oscillators within the visual cortex.

Epilepsy and sleep disorders improve in adolescents and adults with Angelman syndrome: A multicenter study on 46 patients.

OBJECTIVE: Actual knowledge on evolution of Angelman syndrome (AS) relies on questionnaire-based cohort studies, phone interviews, or small retrospective cohort studies focused on specific clinical-genetic features. These reports provide conflicting results. The aim of this study was to assess the long-term outcome of epilepsy, sleep disorders, and EEG in a vast series of AS subjects. METHODS: We collected patients with genetically confirmed AS, aged ≥14years, followed in three tertiary epilepsy Centers or attending the meetings of the Italian Organization for AS (OrSA). Retrospective clinical and EEG data were retrieved from hospital archives or family documents. At index evaluation (IE) (last visit at tertiary Centers or single visit during OrSA meetings), caregivers were interviewed about anamnestic data and filled questionnaires on sleep disorders and daily-living skills. Patients underwent general and neurologic evaluation, and video-EEG recordings. All available EEGs were analyzed to compare evolution of spike-wave index (SWI) over the years. RESULTS: Forty-six subjects aged 14-45years were included: 24 from tertiary Centers, 22 from OrSA meetings. During childhood, 42/46 (91.3%) had seizures, which improved over the years in all subjects. Among patients with epilepsy, 27(64%) became seizure-free at a median age of 10years and 4 remained seizure-free even after antiepileptic withdrawal. During childhood, 39/46 (84.8%) had sleep disorders, which improved in 27/39 (69%) over the years. At IE, daily-living skills corresponded to age≤1.6years in 29/46 (63%). Electroencephalogram showed typical AS patterns in 35/46 (76.1%). In EEGs recorded from 10 patients, SWI was not significantly different between infancy/childhood and adolescence/adulthood. CONCLUSION: Improvement of epilepsy or sleep disorders should not disregard the clinical suspicion of AS in adolescent or adult patients with suggestive features. Drug withdrawal might be considered in the management of epilepsy despite the persistence of epileptiform abnormalities.

Somatosensory evoked potential amplitudes correlate with long-term consciousness recovery in patients with unresponsive wakefulness syndrome.

OBJECTIVE: To prospectively investigate relationships of cortical somatosensory evoked potential (SEP) amplitudes with consciousness recovery and disability in the year following brain injury in patients with vegetative state/unresponsive wakefulness syndrome (VS/UWS). METHODS: SEPs of 42 patients with VS/UWS were recorded 51.7 ± 23.3 days post-injury. N20-P25 amplitudes were compared between patients with and without consciousness recovery at 6 months and 1 year post-injury. RESULTS: SEPs were present in 21 patients and bilaterally absent in 21 patients. N20-P25 amplitudes were significantly higher in patients who recovered consciousness than in those who died or did not recover consciousness at 6 months (median, 4.6 vs. 1.9 µV; P = 0.004) and 1 year (median, 4.6 vs. 2.1 µV; P = 0.02) after injury. The lowest N20-P25 amplitude in a patient who recovered consciousness was 2.15 µV. N20-P25 amplitudes correlated significantly with Coma Recovery Scale-Revised and Disability Rating Scale scores at 6 months and 1 year post-injury (both P < 0.05). CONCLUSIONS: In patients with VS/UWS, SEP amplitudes are related to consciousness recovery and disability at 6 months and 1 year post-injury. SIGNIFICANCE: The evaluation of SEP amplitudes can help to refine prognoses for patients with VS/UWS.

Dystonia in Angelman syndrome: a common, unrecognized clinical finding.

INTRODUCTION: Angelman syndrome (AS) is a neurodevelopmental disorder characterized by cognitive disability, speech impairment, hyperactivity and seizures. Movement disorders have been reported in almost all AS subjects and they are described as "tremulous movements of limbs, unsteadiness, clumsiness or quick, jerky motions". The presence of dystonia has barely been mentioned in subjects with AS and has never been studied in detail. The purpose of this study is to evaluate the prevalence, clinical features and severity of dystonia in a series of adolescents and adults with AS. METHODS: Whole body video recordings of patients with genetically confirmed AS were evaluated. Dystonia was evaluated by mean of the movement subscale of Burke-Fahn-Marsden Dystonia Rating Scale (BFM). RESULTS: Forty-four subjects with AS were evaluated. Fourteen recordings were excluded due to poor cooperation. We finally analyzed data of 30 subjects (15 F) with a median age of 28 years (range 15-51). Dystonia was present in 28/30 (93.3%) subjects. Among these, dystonia involved the upper limbs in 28/28 (100%), lower limbs in 8/28 (28.5%), mouth in 7/28 (25%), neck in 3/28 (10.7%), trunk in 1/28 (3.6%). Severity of dystonia ranged from slight to moderate. There was a linear correlation between severity of dystonia and increasing age. There was no difference in terms of severity of dystonia among genetic subgroups. CONCLUSIONS: Dystonia is a common and previously underrecognized clinical feature of adults and adolescents with AS.

COVID-19 Neuromuscular Involvement in Post-Acute Rehabilitation.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with muscle and nerve injuries as a consequence of prolonged critical illness or the infection itself. In this study, we evaluated neuromuscular involvement in patients who underwent post-acute intensive rehabilitation after COVID-19. METHODS: Clinical and neurophysiological evaluations, including nerve conduction studies and electromyography, were performed on 21 consecutive patients admitted for rehabilitation after COVID-19. RESULTS: Clinical signs suggesting muscle or nerve involvement (weakness, reduced deep tendon reflexes, impaired sensitivity, abnormal gait) were found in 19 patients. Neurophysiological examinations confirmed neuromuscular involvement in 17 patients: a likely association of critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) was found in 5 patients; CIM alone was found in 4 patients; axonal sensory-motor polyneuropathy was found in 4 patients (CIP in 2 patients, metabolic polyneuropathy in 2 patients); Guillain-Barré syndrome was found in 2 patients (classical demyelinating sensory-motor polyneuropathy and acute motor axonal neuropathy, respectively); peroneal nerve injury was found in 1 patient; and pre-existing L4 radiculopathy was found in 1 patient. CONCLUSIONS: Neuromuscular involvement is a very common finding among patients admitted for rehabilitation after COVID-19, and proper investigation should be conducted when muscle or nerve injury is suspected for adequate rehabilitative strategy planning.

Critical illness myopathy after COVID-19.

This paper describes a patient who developed diffuse and symmetrical muscle weakness after a long stay in the intensive care unit (ICU) due to coronavirus disease 2019 (COVID-19). The patient underwent a neurophysiological protocol, including nerve conduction studies, concentric needle electromyography (EMG) of the proximal and distal muscles, and direct muscle stimulation (DMS). Nerve conduction studies showed normal sensory conduction and low-amplitude compound muscle action potentials (CMAPs). EMG revealed signs of myopathy, which were more pronounced in the lower limbs. The post-DMS CMAP was absent in the quadriceps and of reduced amplitude in the tibialis anterior muscle. Based on these clinical and neurophysiological findings, a diagnosis of critical illness myopathy was made according to the current diagnostic criteria. Given the large number of patients with COVID-19 who require long ICU stays, many are very likely to develop ICU-acquired weakness, as did the patient described here. Health systems must plan to provide adequate access to rehabilitative facilities for both pulmonary and motor rehabilitative treatment after COVID-19.

Connectivity measures suggest a sub-cortical generator of myoclonus in Angelman syndrome.

OBJECTIVE: The clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients. METHODS: We performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC). RESULTS: Twenty-four patients (aged 3-35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ±â€¯1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group. CONCLUSIONS: These neurophysiological findings suggest a subcortical generator of myoclonus in AS. SIGNIFICANCE: Myoclonus in AS has not a cortical origin as previously hypothesised.

Digital cineradiographic study of swallowing in infants with neurologic disease. Our experience.

PURPOSE: The study is aimed at proposing the use of digital cineradiography in the evaluation of swallowing disorders in children affected by severe neurological or developmental disability, in order to correctly identify these conditions and provide therapeutic approaches that could solve their feeding problem, improve their nutritional conditions and decrease the risk of infections. MATERIALS AND METHODS: In the period between March 2001 and July 2003, 12 children (8 males and 4 females), aged between 9 months and 13 years, (average 6.2 years), affected by severe neurological or psychomotor disorders were evaluated with digital cineradiography. This investigation was requested for recurrent pulmonary infections and/or dysphagia with weight loss. All the examinations were performed with radio-controlled equipment provided with a digital C arm. RESULTS: Using the above mentioned technique, in all 12 patients, it was possible to differentiate those with disorders of the oral and/or pharyngeal swallowing phase (9/12) from those without swallowing dysfunction (3/12). In 9/9 patients passage of contrast medium into the upper airways was observed during swallowing: in 2 of them this was limited to the laryngeal vestibule (sub-epiglottic penetration), while in 7/9 cases aspiration of contrast medium into the trachea (5/9) or into the right bronchus (1/9) or into both bronchi (1/9) was recorded. In one patient the aspiration decreased in the sequences acquired with hyperflexion of the head. In 3/9 patients we recorded the transition of contrast medium into the nasopharynx during swallowing caused by incomplete closing of the oropharyngeal isthmus by the soft palate. In 3/9 patients there was incomplete clearing of the pharynx with contrast medium deposition in glosso-epiglottic vallecules and in the pyriform sinuses; only in one case did this stagnation result in post-swallowing aspiration. More than one disorder was found in 5/9 patients, and one only in 4/9. CONCLUSIONS: On the basis of our preliminary data it is possible to conclude that the dynamic swallowing study with digital technique allows a clear-cut evaluation of the swallowing process with minimum discomfort for the patient. On the other hand, the technique exposes to the risk of ionizing radiation; however, in consideration of the important clinical and therapeutic implications and in agreement with the literature, we believe that the importance of the information provided by the technique outweighs the risks linked to radiations.