Spontaneous Cerebellar Hemorrhage

You’ve been diagnosed with a cerebellar hemorrhage — what does this mean?

This diagnosis means that a blood vessel within the cerebellum has ruptured and a hematoma has formed in a particularly confined space in the back of the skull (the posterior fossa). This can:

• compress the cerebellum, causing severe imbalance, incoordination, and vertigo,
• compress the brainstem, which regulates breathing and cardiovascular function,
• obstruct the fourth ventricle, leading to hydrocephalus and increased intracranial pressure.

For you and your family, this is a critical but treatable condition where rapid assessment by a specialized team (neurosurgery, neurology, neurocritical care) can be decisive for the outcome.

What exactly is spontaneous cerebellar hemorrhage?

“Spontaneous” means the hemorrhage was not triggered by head trauma and is not immediately attributable to an obvious structural lesion such as a tumor or a known vascular malformation. Typically:

• it arises from rupture of a small perforating arteriole near the dentate nucleus region,
• blood dissects through cerebellar tissue and may extend across adjacent regions,
• it often extends into the fourth ventricle, obstructing CSF pathways and precipitating hydrocephalus,
• more rarely, it extends directly into the brainstem (a particularly severe scenario).

Cerebellar hemorrhage is a neurosurgical emergency because the posterior fossa is anatomically tight: even a “moderate” bleed can rapidly compress vital structures.

Causes & risk factors

The most common underlying causes include:

• Hypertension — responsible for ≥60% of cases. In up to ~20%, a hypertensive crisis is present at onset.
• Cerebral amyloid angiopathy — typically in older patients with fragile, bleeding-prone vessels.
• Coagulation disorders — congenital or acquired (liver disease, thrombocytopenia, etc.).
• Medications — anticoagulants (warfarin, DOACs) and antiplatelet agents, particularly if not optimally managed.
• Heavy alcohol use or stimulant exposure (cocaine, amphetamines).

In 15–20% of patients, there is a history of a prior stroke (ischemic or hemorrhagic), and in some cases the hemorrhage may represent hemorrhagic transformation of a silent (prior) cerebellar infarct.

The most important modifiable factor is excellent long-term blood pressure control.

Symptoms & clinical course

Symptoms typically begin abruptly and may include:

• severe vertigo/dizziness,
• marked gait instability, falls, inability to stand or walk,
• headache—often occipital or posterior neck (suboccipital),
• nausea and repeated vomiting,
• diplopia, blurred vision, nystagmus,
• dysarthria (slurred or difficult speech),
• decreased level of consciousness (somnolence to coma).

A key danger is that deterioration can be rapid and unpredictable, often within the first 24–72 hours, as:

• the hematoma may expand,
• perihematomal edema increases,
• hydrocephalus can develop and trigger sudden neurologic decline.

Approximately one-third of patients arrive at the hospital already in a comatose state.

How is the diagnosis made, and what does imaging show?

Diagnosis is based on the clinical presentation and, critically, urgent neuroimaging:

• Non-contrast head CT — the acute-phase gold standard: rapidly identifies the hemorrhage location and size, whether it involves a hemisphere or the vermis, extension into the fourth ventricle, hydrocephalus, and posterior fossa “tightness” (basal cistern effacement).
• MRI — often complementary, especially if there is concern for an underlying lesion, prior silent events, or infarction.
• Angiography / CTA / MRA — in selected cases to evaluate for an underlying vascular lesion (AVM, aneurysm, etc.) when clinically or radiographically suspected.

Imaging features that meaningfully influence management include:

• hematoma size (e.g., diameter > 3 cm is typically considered high risk),
• degree of fourth ventricle compression/obliteration,
• presence of hydrocephalus with third and lateral ventricular enlargement,
• posterior fossa “tightness” (compressed basal cisterns),
• whether the hemorrhage primarily involves the vermis versus a hemisphere—vermis hemorrhages often require intervention at smaller sizes due to proximity to the brainstem.

When is urgent surgery required?

Based on contemporary guideline frameworks (including AHA/ASA) and major clinical series:

Surgical evacuation is generally recommended when:

• the patient is neurologically worsening or presents in moderate-to-severe clinical condition,
• there is compression or obliteration of the fourth ventricle,
• hydrocephalus is present with clinical deterioration,
• the hematoma is generally > 3 cm in diameter (often a lower threshold for vermian hemorrhage),
• there are signs of brainstem compression.

In patients with a good neurological examination (GCS ≥ 13), a small hematoma (< 3 cm), and no hydrocephalus or brainstem compression, careful conservative management may be appropriate—paired with frequent neurologic checks and repeat CT imaging.

What surgical options are available?

The goals of surgery are to decompress the posterior fossa, evacuate the hematoma, and restore cerebrospinal fluid (CSF) pathways.

Suboccipital craniectomy/craniotomy with hematoma evacuation

• An incision is performed in the midline or slightly paramedian in the posterior scalp.
• A portion of occipital bone is removed (suboccipital craniectomy or craniotomy).
• The dura is opened; the hematoma is accessed and removed using microsurgical technique.
• Meticulous hemostasis is achieved, and duraplasty is commonly performed using a synthetic graft.

External ventricular drainage (EVD) in combination with evacuation

• An external ventricular drain may be placed to treat acute hydrocephalus.
• It is most often used in conjunction with hematoma evacuation, because CSF drainage alone rarely addresses the primary mass effect in clinically significant cases.

Minimally invasive approaches (endoscopic evacuation, stereotactic catheter drainage with thrombolytics) have a more limited role in cerebellar hemorrhage and are typically reserved for highly selected cases in specialized centers, depending on hematoma morphology and anatomy.

CSF drainage, EVD & the risk of “upward” herniation

Placement of an external ventricular drain (EVD) can rapidly relieve hydrocephalus. However:

• if used as the only intervention without hematoma evacuation, it may be insufficient—because the dominant problem can remain direct brainstem compression.
• there is a theoretical risk of upward transtentorial herniation if supratentorial pressure is relieved too quickly while a significant posterior fossa mass effect persists.

For this reason, in severe cerebellar hemorrhage, CSF diversion is typically:

• used in combination with surgical evacuation, or
• performed with careful drainage level settings (e.g., 15–20 cm H₂O) and close monitoring when the hematoma is small and the clinical situation allows.

Prognosis, risks & outcomes

Spontaneous cerebellar hemorrhage carries a substantial mortality risk, with some historical series reporting rates as high as 50–75% in severe presentations. In more contemporary cohorts with timely surgical intervention and neurocritical care:

• mortality is often reported in the range of ~25–55%,
• a meaningful proportion of survivors (~50% in some series) can achieve favorable functional outcomes (GOS 4–5).

Prognostic factors include:

• Initial neurological status (GCS) — higher is generally associated with better outcomes.
• Hematoma size and the degree of fourth ventricle/brainstem compression.
• Presence of hydrocephalus and posterior fossa “tightness.”
• Medical comorbidities (diabetes, liver disease, hematologic disorders, etc.).
• Time to surgical decompression when indicated.

Even in severe presentations, rapid surgical decompression in patients with preserved brainstem function—even if minimal—can improve survival and outcomes, which is why an aggressive, time-sensitive approach is often appropriate.

Daily life & rehabilitation after cerebellar hemorrhage

Survivors may experience:

• imbalance, ataxia, and coordination deficits (often with falls),
• speech articulation difficulty,
• fatigue, dizziness, headaches,
• anxiety and mood changes.

Interdisciplinary rehabilitation is essential:

• physical therapy for balance and gait training,
• occupational therapy for fine motor skills and activities of daily living,
• speech therapy when indicated,
• neuropsychological support and counseling for the patient and family.

The objective is to restore the highest possible level of independence and adapt the home and work environment to new needs.

When is it an emergency, and what should I do?

Cerebellar hemorrhage is always a medical emergency. Call your local emergency number immediately if you or someone near you develops:

• sudden severe vertigo with inability to stand or walk,
• marked gait instability or coordination loss,
• a sudden intense headache with vomiting,
• diplopia, blurred vision, or abnormal eye movements,
• sudden somnolence, confusion, or loss of consciousness.