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A 59-year-old man was admitted with a diagnosis of acute cerebellar infarct. The next day his level of consciousness deteriorated (Glasgow Coma Score 5) and repeat computed tomography (CT) brain scan showed subtle signs of hydrocephalus. Following neurosurgical intervention, he recovered and is now walking with a frame and assistance. The CT changes of hydrocephalus were subtle and difficult to spot. Recognition of these signs of hydrocephalus and prompt neurosurgical intervention were lifesaving.
Neurosurgical intervention for patients with cerebellar infarct, complicated by hydrocephalus, is potentially lifesaving, even if level of consciousness is profoundly impaired.
A 59-year-old man presented to the accident and emergency department with sudden onset of collapse, headache and left sided weakness. On examination, blood pressure was 142/80 mm Hg and heart rate was 100 beats/min with regular rate and rhythm. Power in the left upper and lower limb was grade 3/5, with incoordination. Right limb power intact and cranial nerve examination was normal. As he had presented within the 3 h window, he was assessed by a stroke physician and thrombolysis was administered. Initial computed tomography (CT) scan of the brain was normal (fig 1).
The patient was transferred to the acute stroke unit. The following day (20 h following admission) a significant fall in the level of consciousness was noted. Glasgow Coma Scale was documented to be 5/15 (E1, V1, M3). Pupil reaction was noted to be equal and sluggish. Initial conclusion was aspiration pneumonia and the patient was treated accordingly. An urgent CT brain scan was arranged. On the second CT scan (fig 2B), the lateral ventricles are larger and the temporal horn of the lateral ventricle is prominent (fig 2A). The radiological report stated that the third and the lateral ventricles were slightly prominent, but did not state that hydrocephalus was present. The stroke physician reviewed the scans and was suspicious of subtle signs of hydrocephalus secondary to the cerebellar infarct.
The patient was intubated and ventilated. The neurosurgical unit advised a repeat CT brain scan (fig 3), which excluded haemorrhagic transformation of the infarct. However, changes of hydrocephalus persisted.
Immediate transfer was arranged to the regional neurosurgical centre the same night for external ventricular drainage.
The patient made an uneventful postoperative recovery and was transferred back for ongoing rehabilitation. He was eventually able to walk with a frame and assistance.
It is important to recognise the signs of early hydrocephalus. The second CT brain scan shows that the frontal horn of the third ventricle has a rounded appearance and is larger, compared to the first scan (fig 2B, arrow). Furthermore, the second scan shows that the temporal horn of the lateral ventricle is more prominent (fig 2A, arrow) compared to the first scan. Signs of hydrocephalus are frequently difficult to spot on CT, hence it is important to review the brain scans carefully and compare them to previous scans, if available. If the stroke physician had not spotted these signs, the patient may not have benefited from neurosurgical intervention.
Patients admitted with cerebellar stroke should be observed carefully in a hyperacute stroke unit or high dependency unit. Deterioration in level of consciousness should prompt repeat clinical assessment and CT brain scan. If there are signs suggesting hydrocephalus then urgent neurosurgical opinion should be sought.
There are case reports of neurosurgical intervention benefiting patients with cerebellar stroke, complicated by hydrocephalus, even if the level of consciousness is profoundly impaired.1 This case report is unique as the signs of hydrocephalus were subtle and the radiological report was inconclusive.
The diagnosis of acute ischaemic stroke is obtained on the basis of history and neurological examination, supported by appropriate brain imaging. Thrombolysis is established treatment for ischaemic stroke and should be administered without delay if there are no contraindications and onset of symptoms is within the preceding 3 h.2,3
CT brain scan may not detect evidence of infarction, particularly if performed within the first few hours following onset of symptoms.4,5 Furthermore, CT lacks sensitivity in identification of infarction in the posterior fossa.4 In contrast, CT is reliable for exclusion of symptomatic acute haemorrhage.
Magnetic resonance imaging (MRI) brain scan is more sensitive than CT for the detection of early cerebral infarction and infarction in the posterior fossa.4,5 MRI may be utilised as the first line imaging modality for patients with acute stroke;5 however, in our unit and neighbouring hyperacute stroke units, MRI is not widely available out-of-hours (personal communication). In acute stroke it is appropriate to arrange an urgent CT brain scan as the priority is to exclude haemorrhage to allow administration of thrombolysis.2,3
Cerebellar infarct may present with non-specific symptoms of dizziness, headache, nausea and vomiting.4,6 Not infrequently, the diagnosis is missed and the symptoms attributed to other causes such as gastroenteritis or labrynthitis.4,6 Errors in diagnosis may be prevented by taking a comprehensive history and performing a detailed neurological examination. If the initial CT is normal and diagnostic doubt remains, then an MRI brain scan should be considered. Moreover, based upon clinical judgement, it may be appropriate to arrange and MRI brain scan as the first line investigation for suspected cerebellar infarct; however, this approach depends upon availability of this mode of imaging as discussed above.
In this case, the patient had symptoms and signs of an acute stroke. Thrombolysis was administered appropriately on the basis of the CT brain scan excluding haemorrhage. The cerebellar infarct was not apparent on the initial CT scan but is clearly visible on the second CT scan performed the following day.
This case should remind physicians that urgent neurosurgical intervention for patients with hydrocephalus following cerebellar stroke is potentially lifesaving, even if the level of consciousness is profoundly reduced. National guidelines acknowledge the benefit of neurosurgical intervention in cases of stroke associated with hydrocephalus.2,3
Competing interests: None.
Patient consent: Patient/guardian consent was obtained for publication.