Lowry Wood syndrome
Overview
A rare syndrome characterized by a small head, rapid involuntary eye movements (nystagmus) and abnormal development of the ends of long bones where growth occurs.
Symptoms
* Small birth size * Small head * Multiple epiphyseal dysplasia * Rapid involuntary eye movements * Short stature * Mental retardation * Square iliac bones * Flattened acetabula
Causes
* Vestibular –Peripheral (horizontal rotary nystagmus, slow phase toward hypoactive side, latency, fatigability, and accompanied by vertigo, tinnitus, or deafness): Etiologies include labyrinthitis, vestibular neuronitis, Ménie're's disease, migraine, BPV –Central (asymmetric, rotary nystagmus that changes direction in different gazes, no latency, not fatigable): Etiologies include lesions of cerebellum, pons, or cerebellopontine angle –Horizontal * Gaze-evoked –Physiologic: Fixing on objects with eyes when head is turned (e.g., ballerinas) –Pathologic (asymmetric): Etiologies include toxic-metabolic lesions, cerebellar or pontine lesions * Dissociated (different nystagmus between eyes): Etiologies include internuclear ophthalmoplegia of multiple sclerosis or cerebral disease * Periodic alternating nystagmus (cervicomedullary junction) * Downbeat (cervicomedullary junction, characteristic of syringobulbia) * Upbeat (brainstem or cerebellum when present in primary gaze; drug effect if only present in upgaze) * Drug-induced (e.g., anticonvulsants, sedatives, alcohol ) * Monocular visual loss (ipsilateral slow vertical oscillation) * Head nodding, head turn (due to motor or sensory deficits)
Diagnosis
The basic diagnostic workup includes visual acuity, visual fields, audiogram, caloric testing, and x-rays of the skull, mastoids, and petrous bones. If these are negative or indefinite, a CT scan or MRI of the brain will be necessary. A spinal fluid analysis will help diagnose central nervous system lues and multiple sclerosis. A BSEP or VEP study may be needed to diagnose multiple sclerosis. The help of a neurologic specialist should be sought before ordering expensive diagnostic tests. Cisternography, tomography, and vertebral basilar angiography are occasionally necessary to establish the diagnosis. Magnetic resonance angiography is an excellent noninvasive means of visualizing the vertebral-basilar circulation.
Treatment
* Treat the underlying etiology if possible * Remove offending medications/toxins if possible * Medications to treat the nystagmus (e.g., meclizine for BPV) have varying success * BPV: Otolith repositioning maneuvers (Epley's, Semont's) * Botulinum toxin injection to the appropriate extraocular muscles may be used for severe disabling nystagmus * Congenital nystagmus: Maximize vision by refractive lenses, treat amblyopia (“lazy eye”) if indicated, prism, and/or eye muscle surgery * Vestibular: Vestibular suppressant (meclizine, diazepam), vestibular adaptation exercises * Baclofen may be useful in periodic alternating nystagmus and some congenital nystagmus * Clonazepam for downbeat nystagmus