Okluze velkých mozkových tepen u nemocné se svalovou dystrofií Emery-Dreifuss

During the night, about 3 hours after falling asleep, the patient experienced sudden left movement disorder (there were some dystonic movements on the left side observed and described by her husband) along with marked restlessness. The husband called the emergency service and the patient was admitted to the ICU of the stroke center. Stroke due to embolization to the middle cerebral artery (MCA) was dia gnosed. Brain CT revealed, that penumbra was only aff ected to a small extent; ASPECTS (Alberta Stroke Programm Early CT Scale) was 3 points. CTA of the cerebral arteries showed the occlusion of the terminal section of the internal carotid artery (ICA) on the right side (segment C7) with a transition to the M1/MCA segment (10 mm) (Fig. 1). The patient was consulted at a comprehensive stroke center that did not recommend intravenous thrombolysis or mechanical thrombectomy due to the presence of signifi cant and extensive ischemic changes in the brain tissue. The fi nding was evaluated as an emboligenic occlusion of the distal ICA, most likely of cardiac origin. On the next day, somnolence, dysarthria, dysphagia and left-sided hemiplegia were present. A follow-up CT of the brain was performed with the fi nding of expansively behaving ischemia in the right hemisphere with a midline shift, with a subphalcinic and descending transtentorial herniation (Fig. 2). The patient was transferred to neurosurgery, where an extensive right-sided hemicraniectomy was performed. This was followed by a stay at the Anesthesiology and Resuscitation Department. After disconnection from complete mechanical ventilation (immediate postoperative), she was transferred to a neurological ICU. Here, the patient’s environmental cooperation gradually improved, and passive and active rehabilitation was started. The neurological fi nding was dominated by signifi cant psychological changes with fl uctuations in cooperation, partial neglect syndrome, plegia of the left upper limb, and severe paresis of the left lower limbV noci, asi 3 hodiny po pádu ve spánku, u pacienta došlo k náhlému odchodu pohybová porucha (byly pozorovány dystonické pohyby na levé straně a popsal její manžel) spolu s výrazný neklid. Manžel volal záchrannou službou a pacient byl přijat na JIP iktového centra. Mrtvice v důsledku embolizace do středního mozku arterie (MCA) byla diagnostikována. CT mozku odhalilo, že polostín byla ovlivněna pouze malý rozsah; ASPECTS (Alberta Stroke Pro gramm Early CT Scale) byla 3 body. CTA z mozkové tepny vykazovaly okluzi terminálního úseku vnitřní karotidy tepna (ICA) na pravé straně (segment C7) s přechodem do segmentu M1/MCA (10 mm) (obr. 1). Pacient byl konzultován na komplexní iktové centrum, které ne doporučit nitrožilní trombolýzu popř mechanická trombektomie z důvodu přítomnosti významné a rozsáhlé ischemie změny v mozkové tkáni. Nález byl hodnoceno jako emboligenní okluze distální ICA, pravděpodobně kardiálního původu. Další den ospalost, dysartrie, dysfagie a levostranná hemiplegie byly současnost, dárek. Následné CT mozku bylo prováděno se zjištěním expanzivně ischemie v pravé hemisféře se středočárovým posunem, se subfalcinickým a descendentní transtentoriální herniace (obr. 2). Pacient byl přeložen na neurochirurgii, kde byla provedena rozsáhlá pravostranná hemikraniektomie. Následoval pobyt na Anesteziologii a Oddělení resuscitace. Po odpojení od úplné mechanické ventilace (bezprostředně po operaci), byla převezena na neurologickou JIP. Zde postupně probíhá environmentální spolupráce pacienta zlepšila a byla zahájena pasivní i aktivní rehabilitace. Neurologický nález dominovaly výrazné psychické změny s kolísáním spolupráce, syndrom částečného zanedbávání, plegie levá horní končetina a těžká paréza levé dolní končetin

Neurophysiological evidence for muscle tone reduction by intrathecal baclofen at the brainstem level

OBJECTIVE: Intrathecal baclofen (ITB) is an efficient treatment modality for severe spasticity that is considered to act at the spinal level. Its influence on phasic spasticity is usually determined clinically by testing muscle reflexes, and on tonic spasticity by using scores such as the Modified Ashworth Scale (MAS). Neurophysiological techniques, e.g., soleus H reflex, may provide additional information regarding ITB efficacy. There is, however, only scarce information available on time-response relationships of clinical and neurophysiological measures of spasticity obtained at different levels along the neuroaxis. METHODS: Fourteen patients with severe spastic paraparesis underwent serial evaluation of MAS in upper and lower limbs and serial testing of H reflex in soleus and flexor carpi radialis muscles, T wave in quadriceps and biceps brachii muscles, and blink reflex (BR) with and without prepulse, at baseline, and 15, 30, 60, 90, 120, and 180min following ITB bolus application. RESULTS: ITB bolus application caused significant suppression of soleus H reflex after 15min and of quadriceps T wave after 30min, while MAS dropped significantly after 60min together with significant suppression of BR R2 area without and with prepulse stimulation. H reflex in flexor carpi radialis and T wave in biceps brachii were not significantly suppressed by ITB. The time course of early changes in soleus H(max)/M(max) ratio and quadriceps T wave indicates a suppression of hyperreflexia at the spinal level, while a later reduction of MAS synchronously with suppression of BR with and without prepulse concurs with a brainstem effect of ITB. CONCLUSION: Temporal concurrence between suppression of brainstem reflexes and desired suppression of lower limb muscle hypertonia after ITB bolus application suggests that both may be at least partially mediated from a common CNS region of activity. SIGNIFICANCE: Our data concur with a significant brainstem action of IT

Cutaneous silent periods are not affected by the antihistaminic drug cetirizine

OBJECTIVE: Noxious digital nerve stimulation leads to transient suppression of the electromyographic activity in isometrically contracted hand muscles, known as the "cutaneous silent period" (CSP). To date, neurotransmitters potentially involved in mediating this electromyographic (EMG) suppression remain unknown. Anecdotal observation lead to the hypothesis that antihistaminic medication may counteract nociceptive EMG suppression, as CSPs in one male subject who was accustomed to CSP recordings were temporarily lost following ingestion of an antihistaminic drug for acute rhinitis. A second otherwise healthy male subject, who was on long-term cetirizine for allergic rhinitis, presented without clearly defined CSPs when volunteering for normal values. METHODS: We undertook a systematic study in five healthy subjects (including the one with temporarily lost CSPs) who underwent serial CSP testing after ingestion of 10 mg cetirizine. CSPs were elicited in thenar muscles following digit II and digit V stimulation (20 times sensory threshold, 100 sweeps rectified and averaged) before and 90, 180, and 360 min following intake of medication. RESULTS: CSP onset latency, CSP end latency and CSP duration, as well as the index of suppression did not change significantly following ingestion of 10 mg cetirizine. Repeat study in the subject with no clearly defined CSPs on long-term treatment revealed persistently absent CSPs after a 5-week withdrawal from cetirizine. CONCLUSION: CSPs are not affected by therapeutic doses of the H1 antihistaminic cetirizine. SIGNIFICANCE: Our findings suggest that histamine plays no major role as a neurotransmitter of CSPs

Human Neurobehavioral Effects of Long-Term Exposure to Styrene: A Meta-Analysis

Many reports in the literature suggest that long-term exposure to styrene may exert a variety of effects on the nervous system, including increased choice reaction time and decreased performance of color discrimination and color arrangement tasks. Sufficient information exists to perform a meta-analysis of these observations quantifying the relationships between exposure (estimated from biomarkers) and effects on two measures of central nervous system function: reaction time and color vision. To perform the meta-analysis, we pooled data into a single database for each end point. End-point data were transformed to a common metric of effect magnitude (percentage of baseline). We estimated styrene concentration from biomarkers of exposure and fitted linear least-squares equations to the pooled data to produce dose–effect relationships. Statistically significant relationships were demonstrated between cumulative styrene exposure and increased choice reaction time as well as increased color confusion index. Eight work-years of exposure to 20 ppm styrene was estimated to produce a 6.5% increase in choice reaction time, which has been shown to significantly increase the probability of automobile accidents. The same exposure history was predicted to increase the color confusion index as much as 1.7 additional years of age in men

The cutaneous silent period is preserved in cervical radiculopathy: significance for the diagnosis of cervical myelopathy

Electromyographic (EMG) activity from voluntarily contracting hand muscles undergoes transient suppression following nociceptive fingertip stimulation. This suppression is mediated by a spinal inhibitory reflex designated the cutaneous silent period (CSP). The CSP is abolished or altered in a variety of myelopathic conditions. However, before the CSP can gain acceptance as an aid in the diagnosis of myelopathy, the contribution of non-myelopathic conditions that can interrupt the afferent pathways responsible for the CSP needs to be considered. Accordingly, we examined the effect of radiculopathy on the CSP. Nociceptive stimulation was applied to thumb (C6 dermatome), middle (C7) and little (C8) fingers of 23 patients with cervical radiculopathy. Four or more CSP responses were recorded in abductor pollicis brevis muscle following digital stimulation. The patients had C6 (n = 10), C7 (n = 7), or C8 (n = 6) radiculopathy documented by EMG. A complete CSP was elicited in 21 of 23 patients with comparable latencies and durations irrespective of digit stimulated. We conclude that the CSP is preserved in radiculopathy, probably because afferent impulses are carried by smaller, slower conducting ‘injury-resistant’ A-delta fibers. These results provide important missing evidence that ensures specificity of CSP alterations in the diagnosis of cervical myelopathy. The finding that the CSP is spared in radiculopathy should open the door for investigators and clinicians to adopt this simple spinal inhibitory reflex as a physiologic aid in the diagnosis of spinal cord dysfunction