Mounzer Y. Kassab

We report a case of lateral medullary syndrome (LMS) with extradural origin of the posterior inferior cerebellar artery (PICA). A 45-year-old construction worker presented with acute signs and symptoms of typical LMS. Prolonged work-related neck extension was reported just prior to the onset of symptoms. Cerebral angiography revealed a patent vertebrobasilar tree with an extradural origin of an otherwise normal appearing PICA ipsilaterally. Workup did not show evidence for cardioembolic or atheroembolic source. The presence of an extradural origin of PICA may be considered a predisposing factor for non-traumatic LMS associated with head and neck movement.

Background: Intracranial intra-arterial calcifications (ICAC) are a common finding on head CT examinations, but their significance is not known. The aim of this study is to determine if a relationship exists between ICAC on head CT and the presence of a high-grade atherosclerotic stenosis on cerebral angiography. Methods: This was a retrospective study of 108 consecutive patients admitted to the stroke service at Parkland Hospital in Dallas, Tex., USA. Each patient had undergone a head CT and catheter-based angiographic study to meet the inclusion criteria. Demographic information was recorded along with CT imaging data in regards to the amount of calcification. Angiographic images were reviewed independently, and a comparison was made to determine if calcification was predictive of finding a high-grade stenosis on angiography. Results: A total of 108 consecutive patients with a mean age of 56 ± 12 years were studied. Of the 540 vessels studied, 65 (12%) were found to have a stenosis of ≥50% on angiography, and 71 (13.1%) were found to have a calcium grade of 3 or 4 on head CT. ICAC appeared to be more common in the anterior circulation compared to the posterior circulation. Patients with grade 3 or 4 calcification of an intracranial vessel on head CT were more likely to have a stenosis of ≥50% on cerebral angiography. Conclusions: The presence of ICAC on head CT appears to correlate with the presence of an underlying intracranial stenosis on angiography. Further study is required to validate these preliminary findings.

Summary: To define the clinical significance of EEG “cyclic alternating pattern” (ECAP). ECAP is the periodic presence of a high-voltage slow waves alternating with low voltage irregular faster activity. This term was first described in comatose patients in 1944. It has been less recognized and may be underreported since then. The clinical significance of ECAP in the state of coma remains unknown. We reviewed our prospective EEG database for consecutive patients studied over a period of 4 years (n = 4,819) looking for patterns consistent with ECAP. We reviewed the charts of the patients with the above EEG pattern to define the clinical setting and the eventual outcome. Eleven patients were identified. All patients identified were found to be in the coma state at the time of the EEG. The majority of patients (n = 10) survived the coma, and half returned to the community in good functional status. ECAP is seen rarely in comatose patients. Regardless of the cause of the coma, the presence of ECAP carries an overall good prognosis for both survival and recovery.

The objective of this study was to examine the cerebral circulation during spontaneous migraine attacks and to compare changes to an experimental headache model induced by nitroglycerin (NTG) infusion. This prospective study was carried out in a tertiary care hospital on migraineurs with or without aura. Healthy volunteers served as controls. There were no interventions. Flow velocity (FV) and pulsatility index (PI) were measured in migraineurs between and during headache attacks. In controls, FV and PI of the middle cerebral arteries were performed at baseline and after each IV infusion of 0.125, 0.25 and 0.5 μg/kg/min of NTG. In migraineurs, a significant increase in the mean flow velocity (MFV) in the left vertebral artery (VA) and the PI of the right VA during spontaneous migraine headache was found. In controls, all FV significantly decreased after infusion of NTG. The NTG model produces expected and substantially different vascular effects than those seen with spontaneous migraine headache.

Status epilepticus (SE) is a medical emergency requiring prompt treatment to try to limit mortality and improve outcome. So far, newer antiepileptic drugs (AED) have not assumed a noticeable role in the treatment of SE. This may be in part due to the lack of IV forms for the newer AEDs. The IV form of Levetiracetam (IV-LEV) has recently become available and has a potential role in the treatment of SE. We report two cases of non-convulsive SE that responded favorably to IV-LEV. The first patient is an 83-year-old male with a history of complex partial seizure disorder who presented with impaired consciousness. The second patient is an 82-year-old male with history of old left middle cerebral artery ischemic infarction, who presented with confusion. Both patients were found to have a non-convulsive status epilepticus on electroencephalography (EEG) and treated with IV-LEV. In both cases, electrographic SE stopped with marked clinical improvement. Both patients tolerated the medication well and no significant side effects occurred. IV-LEV may have a potential role in the treatment of non-convulsive status epileptics.

Transcranial Doppler (TCD) is a diagnostic tool that can be used at bedside to assess the cerebral vasculature noninvasively. It is inexpensive, safe, and reliable when compared with other techniques. It can be repeated multiple times and can be used for continuous monitoring if needed. Screening of children with sickle cell disease to assess and prevent ischemic strokes and monitoring for vasospasm after subarachnoid hemorrhage are well established, evidenced based utilizations of TCD. It is useful for the evaluation of occlusive intracranial vascular lesions with many emerging indications in the management of ischemic stroke. TCD with micro-bubble enhancement has comparable sensitivity to transesophageal echocardiogram in detecting right-to-left atrial cardiac shunts. TCD is underused as a clinical tool despite well established indications. The pressure to contain increasing medical cost will likely result in increased utilization of this test in future.