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Hypertensive encephalopathy (HTE) usually presents with progressive headache, confusion, visual disturbance and generalised seizures and may progress to coma and death. It is a common cause of the reversible posterior leucoencephalopathy syndrome,1 now more commonly referred to as the posterior reversible encephalopathy syndrome, as grey matter is often also involved. Cranial imaging typically reveals parieto‐occipital subcortical white matter oedema. The preferential involvement of the parietal and occipital lobes is unexplained but may be linked to the relative paucity of sympathetic innervation of the posterior cerebral arterial circulation. Impairment of autoregulation of cerebral blood flow because of an uncontrolled rise in arterial blood pressure, dilatation of cerebral arterioles and endothelial dysfunction are thought to underlie the vasogenic oedema which occurs.1 We report a rare presentation of uncontrolled hypertension with episodic vertigo and ataxia, isolated cerebellar oedema on cranial MRI and secondary obstructive hydrocephalus.
A 52‐year‐old man presented with a 3 week history of recurrent episodes of severe vertigo, nausea, ataxia and mild headache. The initial episodes improved spontaneously over the course of several days but onset of the third such episode led to his admission to hospital. He had experienced mild persistent bifrontal headache and nocturia for 1 month. He had no visual symptoms. There was no history of head or neck trauma.
Five years previously he was noted to have a tonic left pupil and absent lower limb reflexes and was diagnosed with Holmes–Adie syndrome. He had a 15‐pack‐year history of smoking. There was no other significant past medical history but he did not recall having had his blood pressure measured for many years. His mother had developed hypertension in her forties.
On examination he was alert and orientated; he was not encephalopathic. There was persistent severe hypertension with systolic pressures of 230–255 mm Hg and diastolic pressures of 140–150 mm Hg. There was no postural hypotension. A tonic left pupil was noted. Fundoscopy revealed bilateral papilloedema, arteriovenous (A–V) nipping and exudate formation. Horizontal pursuit eye movements were broken but there was no nystagmus. Speech was not dysarthric and the remainder of the cranial nerve examination was normal. There was evidence of left finger–nose incoordination. Lower limb reflexes were absent. Plantar responses were flexor. Gait was wide based and tandem gait was markedly impaired.
Cranial MRI (fig 11)) on admission revealed swelling of the cerebellum with distortion of the fourth ventricle and extensive signal change within the cerebellar hemispheres, particularly on the left. There was moderate obstructive hydrocephalus. The venous sinuses were patent. There was evidence of minor, chronic, hemispheric deep white matter signal change. There was renal impairment (creatinine 171 μmol/l) and heavy proteinuria. Transthoracic echocardiogram revealed moderate left ventricular hypertrophy. Subsequent investigations excluded secondary causes of hypertension such as hyperaldosteronism, renal artery stenosis or pheochromocytoma. Autonomic function tests, including a tilt table study, revealed no evidence of cardiovascular autonomic failure.
The severe hypertension was treated initially with recurrent oral doses of a calcium channel blocker (modified release nifedipine) titrated against blood pressure. Gradual reduction of blood pressure within the first 12 h was matched by significant clinical improvement: he felt much better, nausea and vertigo settled, and the eye movement abnormalities and ataxia resolved. His renal impairment and proteinuria improved within days. Repeat cranial MRI 5 days after admission (fig 11)) showed almost complete resolution of the cerebellar abnormalities and hydrocephalus. Sustained blood pressure control was achieved using a combination of a long acting angiotensin converting enzyme inhibitor, a calcium channel blocker and a beta blocker.
Although cerebellar involvement is reported in HTE,1,2 it very rarely occurs in isolation and leads to secondary obstructive hydrocephalus.3,4 Several cases with predominant brainstem involvement and resultant hydrocephalus have been reported.5,6 Neurological signs in HTE are not usually focal, and in the rare reported cases in which isolated cerebellar involvement with hydrocephalus was noted, presentation tended to be dramatic with obtundation.3,4 Our patient presented without encephalopathy but with episodic vertigo, nausea and ataxia consistent with more focal cerebellar or vestibular dysfunction. Only one previously reported case occurred in an individual without a documented history of longstanding poorly controlled hypertension, renal failure or diabetes mellitus.3 Our patient had no known significant past medical history, although given the presence of left ventricular hypertrophy and the minor, chronic, white matter changes in the cerebral hemispheres, it is probable that he had unrecognised hypertension for some time. In view of the absence of evidence of more generalised autonomic dysfunction, it is unlikely that the history of Holmes–Adie syndrome is relevant to the current clinical presentation.
In addition to prompt treatment of hypertension, neurosurgical intervention and CSF diversion to relieve obstructive hydrocephalus was necessary in the cases with isolated cerebellar involvement reported previously.3,4 Ventriculostomy placement in those cases did not result in lowering of blood pressure, indicating that hypertension was not secondary to raised intracranial pressure.3 In our patient, prompt but controlled lowering of blood pressure alone led to rapid clinical improvement and resolution of the cerebellar oedema and hydrocephalus. In those rare cases without encephalopathic features or a rapidly deteriorating neurological state, the need for ventricular drainage may be obviated by institution of medical therapy.6 Awareness of this rare reversible cause of obstructive hydrocephalus is important for both neurologists and neurosurgeons.
Competing interests: None.