The observation period after clinical brain death diagnosis according to ancillary tests: differences between supratentorial and infratentorial brain injury.

OBJECTIVE: To determine the optimal observation period (OBP) in adults with a clinical diagnosis of brain death (BD) using electroencephalography (EEG) or computerized tomography angiography (CTA). METHODS: We conducted a retrospective observational analysis of adult patients with a diagnosis of BD from January 2000 to February 2017. The optimal OBP was defined as the minimum time interval from the first complete clinical neurological examination (CNE) that ensures that neither a second CNE nor any ancillary test (AT) performed after this period would fail to confirm BD. RESULTS: The study sample included 447 patients. In the supratentorial group, the first AT confirmed BD in 389 cases (98%), but in 8 (2%) cases the complementary test was incongruent. In this group, 8 of 245 patients in whom the first AT was carried out within the first 2 h after a complete CNE had a non-confirmatory test of BD versus none of 152 in whom the first AT was delayed more than 2 h (3.0% vs 0.0%; p = 0.026). In the infratentorial group, we found a higher probability of obtaining a first non-confirmatory AT of BD (34% vs 2%; p = 0.0001) and an OBP greater than 32.5 h was necessary to confirm a BD diagnosis. CONCLUSIONS: We found important differences in the confirmation of BD diagnosis between primary supratentorial and infratentorial lesion, and identified an optimal OBP of 2 h in patients with supratentorial lesions. By contrast, in primary posterior fossa/infratentorial lesions, the determination of an optimal OPB remains less accurate and hence more challenging.

Subacute Encephalopathy With Seizures in Alcoholics (SESA) Presenting as Focal Nonconvulsive Status Epilepticus.

PURPOSE: To acquaint readers with the underrecognized subacute encephalopathy with seizures in chronic alcoholics (SESA) that has more recently been associated with different types of status epilepticus. METHODS: Case reports and review of the literature on SESA and nonconvulsive status epilepticus (NCSE). RESULTS: Two cases: one with alternating bifrontoparietal NCSE, and one with focal, confusional NCSE, with imaging and EEG correlates. CONCLUSION: Underrecognized SESA may present as NCSE with focal clinical, EEG and reversible diffusion-weighted MRI abnormalities, warranting expedited diagnosis and antiseizure treatment to minimize morbidity.

When is "brainstem death" brain death? The case for ancillary testing in primary infratentorial brain lesion.

The widely accepted concept of brain death (BD) comprises the demonstration of irreversible coma in combination with the loss of brainstem reflexes and irreversible apnea. In some countries the combined clinical finding of coma, apnea, and loss of all tested brainstem reflexes ("brainstem death") is sufficient for diagnosing BD irrespective of the primary location of brain lesion. The present article aims to substantiate the need for ancillary testing in patients with primary infratentorial brain lesions. Anatomically, the "brainstem-death" syndrome can theoretically occur without relevant lesion of the mesopontine tegmental reticular formation (MPT-RF). Thus, a brainstem lesion may cause an apneic total locked-in syndrome, a rare syndrome with preserved capability for consciousness, mimicking "brainstem death". Findings in animals and humans have shown that alpha- or alpha/theta- EEG patterns in case of isolated brainstem lesion indicate intactness of relevant parts of the MPT-RF. In such patients the presence of irreversible coma has to be doubted, and the potential capacity for some degree of consciousness cannot be excluded as long as the EEG activity persists. Consequently the demonstration of either ancillary finding, electro-cortical inactivity or, preferably, cerebral circulatory arrest, is mandatory for diagnosing BD in patients with a primary infratentorial brain lesion.

Magnetic resonance imaging of lower limb musculature in acute motor axonal neuropathy.

Magnetic resonance imaging (MRI) is an extremely useful technique to diagnose muscle denervation. This report presents an acute motor axonal neuropathy (AMAN) patient in whom, over 2 years, serial clinical-electrophysiological evaluation and MRI examination of lower limb musculature were performed. A 74-year-old patient was admitted with a 24-h history of ascending weakness culminating a few days later in flaccid and areflexic tetraplegia, which was followed by progressive improvement except for severe residual paresis of foot flexors/extensors. Electrophysiological studies showed motor nerve conduction abnormalities characteristic of AMAN, and profuse signs of active denervation in foot and lower leg muscles, and to a much lesser degree in the thigh muscles. On MRI, T2- and T2-fat suppressed (T2FS) images showed an early (up to month 2 after onset) and subtle hypersignal of all four lower leg muscle compartments evolving to an extensive and widespread hypersignal (as of month 6). Progressive hypersignal of lower leg musculature on T1-weighted images, indicative of fatty atrophy, was detected as of the first year. Thigh and pelvic musculature exhibited early and reversible hypersignal on T2 and T2FS images. There was good concordance between clinico-electrophysiological and MRI findings. We conclude that serial MRI may be very useful to evaluate the extent of muscle denervation and to assess clinical course in AMAN.

[Nonconvulsive status epilepticus in comatose adults]. / Estado epiléptico no convulsivo en adultos en coma.

INTRODUCTION: Nonconvulsive status epilepticus (SE) is a term used to denote a range of conditions in which electrographic seizure activity is prolonged and results in nonconvulsive clinical symptoms. Nowadays, some experts on nonconvulsive SE have emphasized the utility on the clinical practice to consider the classification taking in account both the clinical setting and the severity of consciousness impairment, differentiating between ambulatory patients (from almost normal mental state to stupor) which includes absence SE and complex partial SE; and nonconvulsive SE in coma. AIM: To review the literature in relation to the diagnosis of nonconvulsive SE in comatose and/or critically ill patients. DEVELOPMENT: Nonconvulsive SE has been reported with surprising frequency in a wide variety of acute neurological processes such as cerebrovascular disease, anoxia, subarachnoid hemorrhage, cranial trauma, encephalitis and following convulsive SE. CONCLUSIONS: Nonconvulsive seizures and episodes of nonconvulsive SE in patients with severe impairment of consciousness are frequent and, therefore, continuous EEG monitoring is an essential neurophysiologic tool in the evaluation of comatose subjects. EEG interpretation in patients with nonconvulsive SE may be particularly difficult and problematic and, therefore, requires expert knowledge and a clinical and neurophysiologic specific training.