Huy had previously been diagnosed with syringomyelia, but his symptoms recently worsened. Medication provided no relief, and he experienced weak grip, difficulty lifting heavy objects, finger spasms, and increased headaches with exertion. A computed tomography (CT) scan of his brain and spine at Tam Anh General Hospital Hanoi showed no intracranial hemorrhage or mass. However, it revealed that his cerebellar tonsils had descended approximately 13 mm below the foramen magnum.

Master, Doctor Bui Khuong Duy, from the Department of Neurosurgery - Spine at Tam Anh General Hospital Hanoi, diagnosed Huy with Arnold-Chiari type I accompanied by cervical syringomyelia from vertebrae C2 to T3, spanning about 14 cm. The patient presented with typical clinical and subclinical manifestations of Chiari malformation type I, including occipital headaches, dizziness, numbness and pain in the neck, shoulders, and back radiating to both arms, and hand muscle atrophy. Magnetic resonance imaging (MRI) of the brain confirmed cerebellar tonsil herniation through the foramen magnum, along with syringomyelia.

This congenital defect is characterized by the descent of the cerebellar tonsils through the foramen magnum, with an estimated prevalence of about 1/100,000 people. Chiari malformation can cause diverse neurological symptoms, sometimes presenting acutely similar to a stroke, which can lead to misdiagnosis initially.

Doctor Duy consults with Huy. Photo: Tam Anh General Hospital

The microsurgery was performed under general anesthesia. Doctors made an 8 cm incision in the occipital region, enlarged the foramen magnum, and resected the posterior arch of C1 to relieve compression. Subsequently, the dura mater was opened and reconstructed using an autologous graft, releasing the cerebellar tonsils and restoring cerebrospinal fluid circulation. The incision was then closed layer by layer.

The surgical process was challenging due to structural changes in the posterior fossa and venous sinuses, which obscured anatomical landmarks. The low descent of the cerebellar tonsils (Chiari I) also limited the surgical field. Therefore, the surgeons performed the procedure meticulously to ensure effectiveness and safety.

Post-surgery, the patient was conscious and breathing stably. He was instructed to begin rehabilitation exercises from the second day to quickly restore motor function. By the third day after the operation, the patient's headaches when coughing and the numbness in both arms had significantly improved. These symptoms are expected to fully recover within approximately two to three weeks. For the syringomyelia, recovery typically takes longer, about six months to one year, as the fluid-filled cavities gradually shrink and neurological function improves.

Early-stage Chiari type I often has no specific clinical manifestations, with many cases discovered incidentally during brain or cervical spine MRI scans. Doctors advise individuals with suspicious symptoms to seek early consultation with a neurologist. Accurate diagnosis helps avoid overlooking neurological conditions like Chiari malformation type I, while also reducing the risk of complications and improving treatment effectiveness.

Hang Tran