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

Thalamic Pain Syndrome, also called Dejerine–Roussy Syndrome, is a severe form of central post-stroke pain arising after damage to the thalamus. Patients develop persistent, often burning neuropathic pain on the side opposite the lesion. It usually follows a thalamic stroke but can occur after other insults. This condition is notoriously challenging to treat and can markedly reduce quality of life. ⚠️

🩺 Etiology

• 🫀 Ischemic stroke: Occlusion of small thalamic perforators (often PCA branches).
• 🩸 Haemorrhagic stroke: Thalamic intracerebral bleed.
• 🎗 Tumours: Infiltrating or compressive lesions.
• 🤕 Trauma: Traumatic brain injury affecting thalamus.
• 🧬 Multiple Sclerosis: Demyelinating plaques in thalamus.

🫀 Vascular Territories Commonly Involved

• Posterior Cerebral Artery (PCA) – thalamogeniculate branches.
• Posterior Choroidal Arteries – posterior thalamus.
• Paramedian thalamic–mesencephalic arteries – from basilar artery.

⚙️ Pathophysiology

The thalamus is the brain’s sensory relay hub. Damage to the VPL (ventroposterolateral) and VPM (ventroposteromedial) nuclei interrupts normal sensory modulation ➝ distorted pain perception. Proposed mechanisms:

• ❌ Deafferentation: Loss of inhibitory inputs ➝ hyperexcitable neurons.
• 🔥 Central sensitization: Heightened responsiveness to inputs.
• ⚖️ Neurochemical imbalance: Altered GABA & glutamate transmission.

👩‍⚕️ Clinical Features

• ⬇️ Contralateral sensory loss initially (numbness, tingling).
• 🔥 Neuropathic pain: Burning, stabbing, or throbbing pain weeks–months later.
• ⚡ Allodynia: Non-painful stimuli (e.g., light touch) cause pain.
• 🔺 Hyperalgesia: Exaggerated pain response.
• 😣 Dysesthesia: Unpleasant abnormal sensations.
• 💔 Emotional impact: Depression/anxiety common.
• 💪 Possible hemiparesis if adjacent motor tracts involved.

🔍 Differential Diagnosis

• 🧠 Other Central Post-Stroke Pain (e.g., brainstem lesions).
• 🖐 CRPS (Complex Regional Pain Syndrome).
• 🧬 Peripheral neuropathy: e.g., diabetic, post-herpetic.
• 🦴 Musculoskeletal pain: Shoulder joint disease after stroke.
• 🧩 Functional/psychogenic pain disorders.

🧪 Investigations

• 🖥 MRI brain: Gold standard for thalamic infarct/haemorrhage.
• 🖼 CT head: Useful acutely (esp. bleed).
• 🧑‍⚕️ Neuro exam: Sensory mapping, reflexes, motor strength.
• ⚡ SSEPs: May show disrupted sensory pathways.
• 🧪 Bloods if metabolic/systemic cause suspected.

💊 Management (often difficult)

Pharmacological

• 💊 Antidepressants: TCAs (amitriptyline), SNRIs (duloxetine, venlafaxine).
• 💊 Anticonvulsants: Gabapentin, pregabalin, carbamazepine, lamotrigine.
• 💊 Analgesics: Tramadol, opioids (caution: dependency, limited efficacy).
• 🩹 Topical: Lidocaine patches, capsaicin cream.
• 💉 NMDA antagonists: Ketamine in refractory cases.

Non-Pharmacological

• 🏃 Physiotherapy: Maintain mobility and reduce discomfort.
• 🧑‍🤝‍🧑 CBT & psychological support: Coping strategies for chronic pain.
• 🛠 Occupational therapy: Aid with daily activities.

Interventional

• 🧲 Deep brain stimulation (DBS): Targeting VPL/VPM nuclei.
• ⚡ Motor cortex stimulation: Epidural cortical stimulation for pain relief.
• 💉 Intrathecal drug delivery: Direct CNS analgesia.
• 📡 Repetitive TMS (rTMS): Non-invasive, promising in trials.

📈 Prognosis

Chronic & difficult to manage. Pain may persist for years despite therapy. Early recognition + multimodal treatment = better function. Psychological & family support are essential.

📚 References

• Klit H, Finnerup NB, Jensen TS. Central post-stroke pain. Lancet Neurol. 2009;8(9):857-868.
• Kim JS. Post-stroke pain. Expert Rev Neurother. 2009;9(5):711-721.
• Canavero S, Bonicalzi V. Central pain syndrome: genesis & treatment. Expert Rev Neurother. 2007.
• Leung A, Fallah A, Cai Y, et al. Motor cortex stimulation in neuropathic pain. Brain Sci. 2018.