Involuntary head vibration movement with nystagmus

Specialty: Pediatrics.

• Spasmus nutans
• head sway with infantile nystagmus
• spasmus nutans triad

Why it occurs

• Benign classic spasmus nutans (self-limited idiopathic disorder characterized by the triad of high-frequency, low-amplitude fast fine nystagmus that is usually asymmetric or monocular, low-frequency involuntary head roll or pitch, and compensatory torticollis; usually begins between 3 and 15 months of age and resolves spontaneously before 3-4 years of age)
• Glioma of the optic pathway or tumor of the chiasmatic/hypothalamic region (neoplasms of the central nervous system that can perfectly imitate the symptoms of spasmus nutans in an indistinguishable way, its exclusion being mandatory in all patients with this presentation)
• Idiopathic congenital nystagmus or associated with ocular albinism or retinal dystrophies (primary visual disorders that present with nystagmus and head adaptation movements)
• Metabolic or demyelinating encephalopathies (rare early-onset neurodegenerative disorders).

Initial workup

High-resolution magnetic resonance imaging (MRI) of the brain and orbits with gadolinium contrast (study of choice that is mandatory in all infants with suspected spasmus nutans or recent-onset asymmetric nystagmus to absolutely rule out gliomas of the optic chiasm or hypothalamic tumors). Comprehensive pediatric ophthalmological examination that includes visual acuity, assessment of ocular alignment, motility, biomicroscopy and fundus under mydriasis. Visual evoked potentials (VEP) and electroretinogram (ERG) if retinal or underlying optic pathway pathology is suspected.

Standard management

• There is no specific pharmacological treatment for classic benign spasmus nutans, since it resolves spontaneously without neurological sequelae. Management is limited to close clinical surveillance by pediatric neurology and ophthalmology. If an optic pathway glioma or other intracranial mass is identified, treatment is performed under specific oncological protocols that may include chemotherapy (using drugs such as Vincristine and Carboplatin) or decompression surgery depending on the location and grade of the tumor.