A 40-year-old male teacher presented with a two-year history of intermittent headaches.
The headache was described as a dull ache at the top of the head, which seemed worse when the patient was under stress and better when he was busy.
There was no aura component, and nausea but no vomiting. He also described a feeling of heavy legs, imbalance and unsteadiness.
Neurological examination revealed normal tone, power, reflexes and sensation. Romberg's test was negative. BP, pulse and temperature were normal. Cranial nerve testing revealed no deficit.
The patient had consulted other GPs with this complaint and had routine blood tests, which included FBC, U&Es, LFTs, bone profile, ESR and CRP. These were all normal and with time, the symptoms passed.
On this occasion, the patient was sent for a CT head scan, which revealed a Chiari type 1 malformation. At the time of review, his symptoms had settled and no further action was necessary.
Pathologist Hans Chiari first described this malformation in postmortem specimens in the 1890s.
A Chiari malformation can be divided into types 1 to 4. The most common and less serious is a type 1 malformation.
Symptoms may include headaches made worse by coughing or straining, neck pain, dizziness and balance problems, numbness/tingling in the arms or legs, blurred vision, difficulty swallowing, tinnitus, insomnia and depression. Symptoms may not develop until adulthood.
A type 1 malformation involves extension of the cerebellar tonsils (the lower part of the cerebellum) into the foramen magnum, without involving the brainstem. The incidence has been estimated at one in 1,000 although this may be increasing owing to greater use of imaging.
An association with Chiari type 1 malformation is the development of a syringomyelia, a tube-shaped cavity in the spinal cord filled with fluid, which can cause symptoms owing to a pressure effect. Symptoms include pain, weakness and stiffness in the back, shoulders or arms.
Symptoms such as headaches respond to analgesics. For worsening symptoms, posterior fossa decompression surgery or spinal laminectomy may be an option. Spontaneous resolution of the malformation is rare, but has been reported.1
Chiari types 2, 3 and 4 are more serious. Type 2 involves extension of both brainstem and cerebellar tissue into the foramen magnum. It is usually accompanied by a myelomeningocele. The term Arnold-Chiari malformation is specific to type 2.
In type 3, the most serious form, the cerebellum and brainstem may herniate into the spinal cord. This can cause severe neurological defects. Type 4 involves an incomplete or underdeveloped cerebellum.
- Dr Gowda is a GP in Sandbach, Cheshire
1. Briganti F, Leone G, Briganti G et al. Spontaneous resolution of Chiari type 1 malformation. A case report and literature review. Neuroradiol J 2013; 26(3): 304-9.