Makindo Medical Notes

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Fahr syndrome, also known as idiopathic basal ganglia calcification, is a rare, inherited or sporadic neurological disorder characterized by abnormal calcification in the basal ganglia, cerebral cortex, and other brain regions. These calcifications lead to various neurological and psychiatric symptoms, making the condition progressive and difficult to manage.

About

• Fahr syndrome refers to familial idiopathic basal ganglia calcification.
• It was first described by Theodor Fahr in 1930, before the advent of CT scanning technology.
• It is extremely rare, with a prevalence of less than 1 in 1,000,000 individuals.

Aetiology

• The calcifications consist of calcium carbonate and calcium phosphate deposits and are primarily located in the following brain structures:
  • Basal Ganglia
  • Thalamus
  • Hippocampus
  • Cerebral cortex
  • Cerebellum (subcortical white matter)
  • Dentate Nucleus
• Fahr syndrome is a progressive neurodegenerative illness often inherited in an autosomal dominant manner, although sporadic cases have been reported.

Clinical Presentation

• The typical age of onset is in the 40s or 50s, although symptoms can appear earlier in life.
• Common neurological and psychiatric symptoms include:
  • Weakness and motor dysfunction
  • Dementia and cognitive decline
  • Seizures and frequent headaches
  • Dysarthria (difficulty speaking)
  • Movement disorders such as:
    • Spasticity
    • Athetosis (involuntary writhing movements)
    • Parkinsonism
    • Dystonia (muscle contractions causing abnormal posture)
    • Chorea (involuntary jerky movements)

Differentials for Brain Calcification

• Hypoparathyroidism
• Vasculitis (inflammation of blood vessels)
• Mitochondrial disorders
• Other causes such as:
  • Infections
  • Radiation or chemotherapy
  • Carbon monoxide poisoning

Clinical Differentials

• Parkinson's disease
• Huntington's disease
• Other forms of dementia (e.g., Alzheimer's disease)

Investigations

• Blood tests: Measure serum calcium, phosphorus, magnesium, parathyroid hormone (PTH), and vitamin D levels to exclude metabolic causes of brain calcification.
• Imaging (CT/MRI): Neuroimaging typically reveals calcifications in the basal ganglia, cerebellum, thalamus, hippocampus, and cerebral cortex. CT scans are more sensitive than MRI for detecting calcifications.
• Genetic testing: Can confirm a diagnosis if a hereditary form of Fahr syndrome is suspected based on family history or clinical presentation.

Management

• Prognosis: The progression of Fahr syndrome varies from person to person, but the disease is generally progressive. Some patients may have minimal symptoms despite significant calcification, while others may develop severe neurological impairment.
• There is no cure for Fahr syndrome, and treatment focuses on managing symptoms and improving quality of life. Supportive treatments may include:
  • Anticonvulsants to manage seizures
  • Physical therapy for motor symptoms
  • Speech therapy for dysarthria
  • Psychiatric care for mood or cognitive disorders
• Due to the variability of symptoms, regular follow-up and individualized management plans are recommended.