Lacunar syndromes

Onset and progression

• One third of patients experience abrupt onset and stepwise progression within hours.
• One third of patients experience gradual worsening over 1-6 days.
• One third of patients experience a TIA the 24 hours preceding a lacunar infarct.
• Many lacunar infarcts are clinically silent.

There are 5 classical presentations and at least 70 other syndromes.

1. Pure motor stroke

• Contralateral hemiparesis. May involve face-arm-leg, face-arm, arm-leg or take the form of isolated facial palsy or isolated monoplegia
• No sensory or visual symptoms.
• No aphasia.

Localization in descending order of frequency:

1. Posterior limb of internal capsule
2. Pons
3. Cerebral peduncle
4. Corona radiata
5. Centrum semiovale
6. Medulla oblongata
7. Bilateral capsular or medullary

2. Sensorimotor stroke

• Contralateral hemiparesis
• Contralateral hemisensory deficit

Localization in descending order of frequency:

1. Thalamocapsular
2. Pons
3. Medulla
4. Corona radiata
5. Posterior limb of internal capsule

3. Pure sensory stroke

• Contralateral sensory deficit affecting all modalities in a cheiro-oral-pedal, cheiro-oral or oral distribution.
• No motor deficit or visual symptoms.

Localization in descending order of frequency:

1. Lateral thalamus
2. Posterior part of corona radiata
3. Pons

4. Ataxic hemiparesis

• Contralateral motor deficit, often more pronounced in the leg than in the arm.
• Contralateral ataxia in arm and/or leg.
• Contralateral sensory deficit may also exist.

Localization in descending order of frequency:

1. Pons
2. Anterior or posterior limb of internal capsule
3. Thalamocapsular
4. Corona radiata

5. Dysarthria-clumsy hand syndrome

• Dysarthria
• Clumsiness in contralateral hand, often characterized by dysmetria, dysrhythmia, dysdiadochokinesia
• Dysphagia
• UMN type of facial palsy may also exist
• Tongue deviation may also exist

Localization in descending order of frequency:

1. Upper basis pontis
2. Corona radiata
3. Genu of internal capsule

Other prominent lacunar syndromes

1. Syndromes with ocular nerve palsies

• Pure hemiplegia with oculomotor palsy
• Pure hemiplegia with abducens palsy
• Pure hemiplegia with horizontal gaze palsy
• Pure hemiplegia or ataxic hemiparesis with one-and-a-half syndrome
• Pure hemiplegia with bilateral ptosis and upgaze palsy
• Oculomotor nerve palsy with contralateral limb ataxia (Claude syndrome)
• Oculomotor nerve palsy with involuntary movements (Benedikt syndrome)

Localization in descending order of frequency:

1. Midbrain
2. Pons (ventral or tegmentum)
3. Posterior limb of internal capsule

2. Syndromes with isolated ophthalmoplegia

• Isolated ocular nerve palsy
• Internuclear ophthalmoplegia
• Vertical gaze palsy
• Pseudoabducens palsy

Localization in descending order of frequency:

1. Midbrain
2. Pons
3. Thalamus
4. Midbrain-diencephalic junction

3. Syndromes with movement disorders

• Chorea
• Athetosis
• Ballism
• Dystonia
• Asterixis with or without hemiataxia and hemisensory deficit
• Parkinsonism

Localization in descending order of frequency:

1. Deep striatum
2. Subthalamic nucleus
3. Thalamus and striatum
4. Thalamus and rostral midbrain
5. Bilateral basal ganglia

4. Syndromes with neuropsychiatric disturbances

• Perseverative behaviour
• Aphasia
• Apathy
• Abulia
• Confusion
• Coma
• Verbal amnesia
• Visual memory deficit
• Akinesia
• Frontal signs

Localization in descending order of frequency:

1. Anterior nuclei of thalamus
2. Bilateral thalamic in paramedian nuclei
3. Caudate and anterior limb of internal capsule