Makindo Medical Notes

Related Subjects: |Acute Stroke Assessment (ROSIER&NIHSS) |Atrial Fibrillation |Atrial Myxoma |Causes of Stroke |Ischaemic Stroke |Cancer and Stroke |Cardioembolic stroke |CT Basics for Stroke |Endocarditis and Stroke |Haemorrhagic Stroke |Stroke Thrombolysis |Hyperacute Stroke Care

🧠 Introduction

A thalamic stroke occurs when blood flow to the thalamus is interrupted. This deep brain structure is a relay hub for sensory, motor, visual, and cognitive signals. Although relatively rare, thalamic strokes cause a wide spectrum of clinical deficits — from hemianesthesia to cognitive and behavioural syndromes. They can be either ischaemic (most often small vessel disease) or haemorrhagic.

🩸 Anatomy & Vascular Supply

The thalamus is supplied by small perforating arteries from the PCA & PComA:

• Paramedian Arteries: P1 PCA, sometimes via Artery of Percheron → bilateral infarcts.
• Thalamogeniculate Arteries: From PCA → lateral thalamus.
• Posterior Choroidal Arteries: Posterior thalamus & choroid plexus.
• Tuberothalamic (Polar) Artery: From PComA → anterior thalamus.

⚠️ Etiology

• Ischaemic: Small vessel lipohyalinosis (HTN/DM), artery-to-artery or cardioembolism, artery of Percheron occlusion.
• Haemorrhagic: Hypertensive bleed, amyloid angiopathy, AVMs, cavernomas, haemorrhagic transformation.
• Other: Deep venous thrombosis, neoplasm infiltration.

🩺 Clinical Features

Depends on arterial territory — think “thalamic strokes = sensory + extras”:

• 🖐 Sensory loss: Contralateral hemianesthesia of all modalities.
• 💪 Motor weakness: If internal capsule fibres are compressed.
• 🔥 Thalamic pain (Dejerine–Roussy): Neuropathic pain weeks later.
• 👁 Visual field loss: Contralateral hemianopia/quadrantanopia.
• ⚖️ Ataxia & tremor: Limb incoordination, intention tremor.
• 👀 Oculomotor signs: Vertical gaze palsy, pupillary changes.
• 🛌 Consciousness changes: Drowsiness, coma (bilateral lesions).
• 🧩 Cognitive/behavioural: Memory loss, apathy, language disturbance (anterior thalamus).

📷 Imaging

• 🖥 Non-contrast CT: Exclude bleed; hyperdense thalamus = ICH.
• 🧲 MRI (DWI): Most sensitive for small infarcts, artery of Percheron lesions.
• 🩻 CTA / MRA: Vessel anatomy & occlusion detection.
• 📡 DSA: For suspected AVM/cavernoma.

🔍 Investigations

• 🧪 Bloods: CBC, U&E, glucose, lipid, coagulation.
• ❤️ Cardiac work-up: ECG (AF), echo (thrombus, PFO).
• 🩺 Vascular studies: Carotid Doppler if extracranial source suspected.
• 📊 Risk profiling: BP, HbA1c, cholesterol.

🚑 Management

Acute

• 🩹 Ischaemic: IV tPA (≤4.5 h), thrombectomy if large vessel, aspirin if no bleed.
• 🩸 Haemorrhagic: BP control, ICP management, ICU monitoring, rare surgical evacuation.

Secondary Prevention

• 💊 Antithrombotics: Antiplatelets or anticoagulants (if AF).
• 💊 Statins: LDL lowering, plaque stabilisation.
• 🩺 Risk factor control: HTN, DM, smoking, lifestyle change.

Rehabilitation

• 🏃 Physio: Motor retraining, gait recovery.
• 🖐 OT: ADL independence, adaptation.
• 🗣 Speech & swallow therapy when indicated.
• 🔥 Pain management: TCAs, gabapentinoids for central pain.
• 🧑‍🤝‍🧑 Psych support: Depression, anxiety screening.

📈 Prognosis

• ✅ Many unilateral strokes recover well with rehab.
• ⚠️ Persistent sensory loss, pain, cognitive change common.
• ☠️ Mortality higher in haemorrhagic forms or large bilateral infarcts.

📚 References

• Schmahmann JD. Vascular syndromes of the thalamus. Stroke. 2003.
• Kumral E, et al. Thalamic infarcts: findings, etiology, prognosis. Neurology. 1995.
• Guenego A, et al. Artery of Percheron infarct patterns. Neuroradiology. 2015.
• AHA/ASA Acute Stroke Guidelines. Stroke. 2019.