Yawning
and stroke
Tumors of the posterior fossa presenting
orthostatic hypotension are rare and only nine
cases have been reported so far. The locations
of almost all these tumors were near the fourth
ventricle and three of them were
hemangioblastoma. A case of a tumor of the
fourth ventricle showing autonomic disturbances
mainly composed of orthostatic hypotension is
reported. A 42-year-old male was admitted to the
Department of Neurology of Chiba University
Hospital on June 25th, 1981 because of three
years' history of autonomic disturbances
including orthostatic syncope, impotence,
urinary disturbance and bowel dysfunction such
as vomiting, diarrhea and constipation. He also
complained of weight loss and staggering of gait
to the left side. On admission, the patient was
emaciated being 50 kg in weight and 172 cm in
height. Neurological examination revealed hippus
of bilateral pupils in light reflex, saccadic
eye movement, slightly hypoactive deep tendon
reflexes, mild terminal oscillations in
bilateral finger-to-nose test, oscillation in
the left heel-to-knee test, staggering tendency
of gait to the left, slightly impaired tactile
and thermal sensations in distal parts of the
legs. Autonomic disturbances were showed by
orthostatic hypotension (BP 104-50 in supine and
70-40 in sitting position), impotence, weight
loss, anorexia, decrease of sweating,
spontaneous yawning and loss of sensation
of bladder fullness. About 5 weeks after
admission, he began to complain of temporal
headache and showed impairment of memory,
drowsiness, paroxysmal apnea and
papilledema.
Autonomic function tests showed BP fall
without increase of heart rate and insufficient
orthostatic increase of plasma noradrenaline
during head-up tilting, no response of BP rise
in cold pressor test, mild BP rise in
noradrenaline infusion test, low R-R interval
variation of ECG, pupillary dilatation to 1.25%
epinephrine and loss of dilatation to 5%
tyrarnine, both of which became normalized
later, and atonie bladder in urodynamic study.
Acetylcholine intradermal injection at
extremities showed almost normal local sweating
of axonal reflex. These results, though net even
in part, suggested that the autonomic
disturbances were mainly derived from central
lesion. Motor nerve conduction velocity and
needle electromyogram were normal.
Brain CT scan showed a round-shaped and
highly contrast-enhanced tumor in the lower hall
of the fourth ventricle. Suboccipital craniotomy
was carried out and a vascular tumor was shown
to exist from dorsal part of medulla to
cerebellar vermis. On biopsy, histological
diagnosis of hemangioblastoma was made.
The feature of this case was that the main
symptoms were not cerebellar ones, but autonomie
disturbances mainly composed of orthostatic
hypotension. The lesions responsible for the
autonomic disturbances were thought te be mainly
in the lower brainstem including vasornotor
center of the medulla oblongata and partly in
the cerebellar vermis which has been
demonstrated to play some role in the control of
the autonomic nervous system. Autonomic
disturbances can be such important clinical
features in cases of posterior fossa tumor that
we should always keep this possibility in mind
in the case of orthostatic hypotension.
