Lateral meningocele syndrome

Overview

Lateral meningocele syndrome, also known as Lehman syndrome, is a very rare genetic connective tissue disorder characterized by the presence of multiple lateral meningoceles-outpouchings of the meninges through the spinal foramina. These meningoceles can cause compression of nearby nerves and spinal cord structures. The syndrome also presents with distinctive facial features, skeletal anomalies, and joint hypermobility. It is considered part of the spectrum of heritable connective tissue diseases and shares some similarities with Marfan and Loeys–Dietz syndromes.

Causes

Lateral meningocele syndrome is caused by mutations in the NOTCH3 gene, which plays a role in cell signaling pathways involved in the development and maintenance of connective tissues. The condition is inherited in an autosomal dominant pattern, meaning only one copy of the mutated gene is sufficient to cause the syndrome. Most cases reported so far have been sporadic, but familial cases with vertical transmission have also been documented.

Symptoms

Symptoms of lateral meningocele syndrome may vary in severity but often include a combination of neurological, skeletal, and connective tissue abnormalities. Common features include:

• Multiple lateral spinal meningoceles – can cause back pain, nerve root compression, or spinal cord dysfunction

• Facial dysmorphism – downslanting palpebral fissures, ptosis (drooping eyelids), a long face, and prominent jaw (prognathism)

• Joint hypermobility – overly flexible joints, which may predispose to dislocations

• Scoliosis and kyphosis – abnormal curvatures of the spine

• Hypotonia – reduced muscle tone, particularly in infancy

• Short stature

• Hearing loss – reported in some cases

Diagnosis

Diagnosis of lateral meningocele syndrome is based on clinical evaluation, imaging studies, and genetic testing. Key diagnostic steps include:

• Magnetic resonance imaging (MRI) – the most effective tool to visualize lateral spinal meningoceles and assess their size and location

• Physical and neurological examination – to detect joint hypermobility, skeletal anomalies, and neurological deficits

• Genetic testing – confirmation of a mutation in the NOTCH3 gene establishes the diagnosis

• Family history review – to assess potential inheritance patterns

Treatment

There is no cure for lateral meningocele syndrome, so treatment focuses on managing symptoms and preventing complications. A multidisciplinary approach is often required, involving neurology, orthopedics, and genetics specialists. Management strategies include:

• Surgical intervention – may be required to remove large or symptomatic meningoceles that cause nerve compression or spinal cord dysfunction

• Pain management – using medications and physical therapy to relieve chronic back or nerve pain

• Orthopedic care – for scoliosis, joint instability, and skeletal deformities

• Hearing support – with hearing aids if necessary

• Regular monitoring – with periodic imaging to evaluate the progression of meningoceles and spinal integrity

Prognosis

The prognosis for individuals with lateral meningocele syndrome varies depending on the severity of spinal involvement and associated complications. Some individuals may lead relatively normal lives with minimal symptoms, while others may experience significant neurological impairment due to spinal cord compression. Early detection and proactive management of complications can greatly improve long-term outcomes. Lifelong follow-up is recommended to monitor for progression of meningocele size and spinal deformities.