Lobar intracerebral hemorrhage

Lobar haemorrhage is a subtype of intracerebral haemorrhage and one the major clinical manifestations of cerebral amyloid angiopathy.

Epidemiology

Primary lobar haemorrhage accounts for approximately 3.9% of acute strokes and 35% of intracerebral haemorrhages¹. Majority

Cerebral amyloid angiopathy is a major risk factor for lobar haemorrhage, with estimates that over 20% of lobar haemorrhages arewere due to cerebral amyloid angiopathy, which (majority of which are typically seen in elderly patients). Hypertension, diabetes, smoking, short stature, dyslipidaemia, anticoagulant use are also significantly associated with primary intracerebral haemorrhage.

Younger patients may also develop lobar haemorrhages, but in such cases there is usually an underlying lesion (e.g. cerebral arteriovenous malformation) ^2,8.

Clinical presentation

Clinical presentation will vary depending on the site and size of the haemorrhage.

• headache and vomiting are the most common symptoms at initial presentation

• seizure can also occur during the onset of the lobar haemorrhage (focal or generalised with a brief duration)

• delirium is increasingly being recognised as a common finding and can be the initial presenting illness

• loss of consciousness or a decrease in GCS

• may present with neglect syndromes or visual field disturbance depending if a frontoparietal or occipital haemorrhage

Pathology

Aetiology

Often the cause of a lobar haemorrhage is never established and the causes, when found, are varied including ^9,10:

• cerebral amyloid angiopathy

• hypertension

  • primary

  • secondary to drug use (e.g. cocaine, amphetamines)

• cerebral aneurysm: both saccular and mycotic

• arteriovenous malformation

• cerebral cavernoma

• brain tumour

  • glioma

  • brain metastasis

• bleeding disorders or coagulopathies

• anticoagulation - therapeutic or supratherapeutic levels

• vasculitis

• cerebral venous thrombosis

One of the strongest predictors of an underlying vascular lesion is the patient's age. The younger a patient, the more likely there is an identifiable cause: CT angiography found causes for haemorrhage in 47% of patients aged 18-45 years, 15% aged 46-70 years, and 4% aged 71-94 ¹¹.

Radiographic features

Overall features of the haemorrhage that suggest an underlying secondary cause are ¹²:

• internal density heterogeneity

• highly irregular margin

• fluid-fluid level

• internal haematocrit level

• extensive surrounding vasogenic oedema

• extensive subarachnoid haemorrhage

CT

CT is usually the modality first obtained and demonstrates a hyperdense collection of blood, located superficially within the lobes of the brain (i.e. not in the basal ganglia). The haemorrhages vary widely in size from only a centimetre or so (often asymptomatic) to extremely large haematomas, and can be estimated using ABC/2 and related formulas. Extension into the subdural or subarachnoid and even intraventricular space may be seen. Intraventricular extension is far more common in basal ganglia haemorrhages.

There are many predictors of haematoma expansion potentially evident on CT, which are discussed in depth in the main intracerebral haemorrhage article.

CT angiography

It is becoming increasingly used in the workup of patients, not only to assess for an underlying abnormality but also to evaluate for the presence of a spot, the so-called CTA spot sign, that is indicative of ongoing bleeding. The presence of such a spot sign correlates, not surprisingly, with a growth of the haemorrhage in the first few hours following the scan and is, again not surprisingly, associated with a poor outcome ^2,3. 

CT perfusion

Recent studies have demonstrated the presence of the spot sign on dynamic-enhancement CT (DECT or CT perfusion) to be an even stronger predictor of haematoma expansion ^4,5, i.e. the most robust factor in predicting outcome ⁸.

MRI

MRI is usually obtained when concern exists that the bleed is from an underlying lesion. Findings depend on the size and age of the bleed (see ageing blood on MRI). 

In cases of primary lobar haemorrhage, multiple small areas of susceptibility-induced signal drop-out may be evident on gradient echo (GRE) or susceptibility weighted (SWI) sequences, in-keeping with previous cerebral microhaemorrhages, suggestive of cerebral amyloid angiopathy.

The presence of single lobar haemorrhage is still part of the Boston criteria for CAA.

Treatment and prognosis

Treatment depends on the age of the patient and the size andor location of the haematoma. Medical management is the mainstay, often palliative iftypically treating the bleedsuspected underlying precipitant.

Management of raised incracranial pressure is enormoussimilar to that of other conditions. Recommendations of supportive measures and lowering of systolic blood pressure have evidence in preventing further bleeding.

In cases of suprathereupetic anticoagulation, cessation of the the anticoagulant is warranted i.e. warfarin discontinuation and rapid reversal. With haematoma growth in an acute haemorrhage, there is moderate evidence of early haemostatic therapy to prevent early and subsequent growth. In situations where the haemorrhage is thought to be derived from inherited or the patientacquired haemophilias i.e. congenital factor VII, some studies recommend treatment with recombinant activated factor VIII.

Neurosurgical intervention currently has significant pre-existing co-morbiditieslittle evidence with very large haematomas.

The recent trial from the Surgical evacuationTreatment for Intracerebral Haemorrhage (STICH) demonstrated little to no overall benefit from early time to surgery when compared to initial conservative management. Surgical removal may be necessaryhave benefit with moderately sizes haematomas, particularly those superficial in location.

Differential diagnosis

The term lobar haemorrhage is often used to denote a primary haemorrhage. As such the differential includes:

• an underlying tumour (e.g. glioblastoma, cerebral metastasis) 

• an underlying vascular malformation (e.g. cerebral arteriovenous malformation)

• haemorrhagic transformation of a cerebral infarct

• haemorrhagic transformation of the venous infarct

Video

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