The course of corticofacial projections in the human brainstem.

Transcranial magnetic stimulation was used to investigate the corticofacial projections in 53 patients with (n = 28) and without (n = 25) central facial paresis due to unifocal ischaemic lesions at different brainstem levels. Lesion topography documented by MRI studies was correlated with the electrophysiological findings. In the majority of patients the corticofacial fibres travel within the ventromedial base of the pons and cross the midline at the level of the facial nucleus. In some individuals, however, we found evidence that corticolingual fibres form an 'aberrant bundle' in a paralemniscal position at the dorsal edge of the pontine base. In other patients the corticofacial fibres loop down into the ventral part of the upper medulla, cross the midline and ascend in the dorsolateral medullary region ipsilaterally to the facial nucleus. The findings suggest that facial paresis due to a brainstem lesion may present as contralateral supranuclear facial paresis by a lesion of the cerebral peduncle, pontine base, the aberrant bundle and the ventral medulla. Supranuclear facial paresis ipsilateral to the lesion side may result from a lesion in the lateral medulla, and facial paresis of the supranuclear type may be imitated by a lesion of the peripheral facial nerve in the dorsolateral medulla with involvement of the lower pons.

[Spontaneous intracranial hypotension syndrome. Clinical, neuroradiological and cerebrospinal fluid findings]. / Spontanes Liquorunterdrucksyndrom. Klinische, neuroradiologische, nuklearmedizinische und Liquor-Befunde.

We report 11 patients with orthostatic headache due to spontaneous intracranial hypotension. Nausea (3 patients) and abducens palsy (2 patients) were the main additional symptoms. Ten patients had CSF pleocytosis (6 to 43 white cells/microliter) and/or increased protein (581 to 1668 mg/l). CT and/or MRI documented bifrontal accentuated subdural hygromas and hematomas in 5 patients. MRI also documented diffuse meningeal gadolinium enhancement in all 4 patients examined, and descent of the brain in one. Cisternography was done in 9 patients and revealed a decreased or absent activity over the convexities and early detection of the tracer in the bladder in all, and a CSF leak at the cervicothoracal junction in 2 patients. Most patients improved with bed rest, increased fluid intake (oral or intravenous), steroids, and/or epidural blood patch. Subdural hematomas increased in 2 patients and have to be drained. Spontaneous intracranial hypotension is due to a CSF leak followed by decreased CSF volume and hydrostatic CSF pressure changes. The locations of the leaks are mainly cervical or at the cervicothoracal junction. MRI always documents diffuse meningeal gadolinium enhancement. Treatment of choice is an epidural blood patch. Surgical treatment may be needed in patients with subdural hematomas or meningeal diverticula. Prognosis is typically good, but subdural hematomas may occasionally lead to an increased intracranial pressure.