Compression of spinal cord and cauda equina in Charcot-Marie-Tooth disease type 1A

Underestimated associated features in CMT neuropathies: clinical indicators for the causative gene?

INTRODUCTION

Charcot-Marie-Tooth neuropathy (CMT) is a genetically heterogeneous group of peripheral neuropathies. In addition to the classical clinical phenotype, additional features can occur.

METHODS

We studied a wide range of additional features in a cohort of 49 genetically confirmed CMT patients and performed a systematic literature revision.

RESULTS

Patients harbored a PMP22 gene alteration (n = 28) or a mutation in MPZ (n = 11), GJB1 (n = 4), LITAF (n = 2), MFN2 (n = 2), INF2 (n = 1), NEFL (n = 1). We identified four novel mutations (3 MPZ, 1 GJB1). A total of 88% presented at least one additional feature. In MPZ patients, we detected hypertrophic nerve roots in 3/4 cases that underwent spinal MRI, and pupillary abnormalities in 27%. In our cohort, restless legs syndrome (RLS) was present in 18%. We describe for the first time RLS associated with LITAF or MFN2 and predominant upper limb involvement with LITAF. Cold-induced hand cramps occurred in 10% (PMP22,MPZ,MFN2), and autonomous nervous system involvement in 18% (PMP22,MPZ, LITAF,MFN2). RLS and respiratory insufficiency were mostly associated with severe neuropathy, and pupillary abnormalities with mild to moderate neuropathy.

CONCLUSIONS

In CMT patients, additional features occur frequently. Some of them might be helpful in orienting genetic diagnosis. Our data broaden the clinical spectrum and genotype-phenotype associations with CMT.

A case of cauda equina syndrome in early-onset chronic inflammatory demyelinating polyneuropathy clinically similar to charcot-marie-tooth disease type 1

To present a case of cauda equina syndrome (CES) caused by chronic inflammatory demyelinating polyneuropathy (CIDP) which seemed clinically similar to Charcot-Marie-Tooth disease type1 (CMT1). CIDP is an immune-mediated polyneuropathy, either progressive or relapsing-remitting. It is a non-hereditary disorder characterized by symmetrical motor and sensory deficits. Rarely, spinal nerve roots can be involved, leading to CES by hypertrophic cauda equina. A 34-year-old man presented with low back pain, radicular pain, bilateral lower-extremity weakness, urinary incontinence, and constipation. He had had musculoskeletal deformities, such as hammertoes and pes cavus, since age 10. Lumbar spine magnetic resonance imaging showed diffuse thickening of the cauda equina. Electrophysiological testing showed increased distal latency, conduction blocks, temporal dispersion, and severe nerve conduction velocity slowing (3 m/s). We were not able to find genetic mutations at the PMP 22, MPZ, PRX, and EGR2 genes. The pathologic findings of the sural nerve biopsy revealed thinly myelinated nerve fibers with Schwann cells proliferation. We performed a decompressive laminectomy, intravenous IgG (IV-IgG) and oral steroid. At 1 week after surgery, most of his symptoms showed marked improvements except foot deformities. There was no relapse or aggravation of disease for 3 years. We diagnosed the case as an early-onset CIDP with cauda equine syndrome, whose initial clinical findings were similar to those of CMT1, and successfully managed with decompressive laminectomy, IV-IgG and oral steroid.

Myoclonic seizures in a patient with Charcot-Marie-tooth disease

Charcot-Marie-Tooth disease affects both motor and sensory peripheral nerves, with broad variability in its clinical and pathologic expression. The involvement of the central nervous system in this disease has been reported in the past, and on two occasions Charcot-Marie-Tooth disease was associated with myoclonic seizures. The previously reported patients with associated Charcot-Marie-Tooth disease and seizures developed a severe disease and died at a young age. This report describes a now 8-year-old male with Charcot-Marie-Tooth disease type 1A associated with myoclonic seizures and developmental delay. Genetic studies established for the first time the duplication of the PMP-22 gene in a patient with this unusual association, confirming the diagnosis. The patient was treated with carbamazepine, valproate, and lamotrigine, has been seizure-free for over 2 years, and was successfully weaned from his medications.

[Charcot-Marie-Tooth disease associated with syringomyelia revealed by urinary disorders]

PURPOSE

Charcot-Marie-Tooth (CMT) disease is characterized by genetic and clinical heterogeneity. The occurrence of urinary disorders is unusual and requires further investigation. CMT disease and syringomyelia are not usually associated. Moreover, primary urinary signs in syringomyelia are not frequent.

CASE REPORT

An 11-year-old girl with CMT disease 1A duplication presented with motor deficit of the leg associated with urinary disorders. Urodynamic study revealed neurogenic detrusor overactivity, and magnetic resonance imaging confirmed syringomyelia extending from T11 to an L1 located conus.

DISCUSSION

Review of the literature confirmed the possibility of primary urinary signs in syringomyelia, with only one case of CMT and urinary signs described. In this case, the diagnosis was radicullar and medullar compression by a hypertrophic nerve formation called an "onion bulb" reflecting the demyelinisation and remyelinisation cycle.

CONCLUSION

Urinary signs in CMT disease are exceptional and require investigation into the possibility of a central lesion.

17p duplicated Charcot-Marie-Tooth 1A: characteristics of a new population

The most frequent type of Charcot-Marie-Tooth (CMT) neuropathy is that associated with the 17p11.2-p12 chromosome duplication, whose characteristics have been well described in European and North American populations. In this study, we analyzed a Brazilian population exhibiting the mutation, found in 57 patients from 42 families (79%) of a cohort of 53 families with demyelinating CMT. Almost 20% of the duplicated cases were sporadic. In 77% of the duplicated families the mutation event occurred in the hot spot area of the CMT1A-Rep region. Forty-five percent of patients were females, 84% were Caucasians and 13% of African descent. Distal limb weakness was the most frequent abnormality, appearing in 84% of patients, although uncommon manifestations such as severe proximal weakness, floppy baby syndrome, diaphragmatic weakness and severe scoliosis were also observed. One patient was wheelchair-bound, and three suffered severe hand weakness. Sensory abnormalities were detected in 84% of the cases, but 80% were unaware of this impairment. Twelve patients complained of positive sensory manifestations such as pain and paresthesias. Progression was reported by 40%. Motor conduction velocities in the upper limbs were always less than 35 m/s, and less than 30.4 m/s in the peroneal nerve. The findings of this study expand the clinical spectrum of the disease.

Conus medulla-cauda compression from nerve root hypertrophy in a child with Dejerine-Sottas syndrome: improvement with laminectomy and duraplasty. Case report

This 7-year-old boy with Dejerine-Sottas syndrome caused by a mutation in the myelin protein zero gene began to suffer rapid deterioration with increasing leg weakness, loss of the ability to ambulate, and bowel and bladder incontinence. Magnetic resonance imaging of the spine revealed nerve root hypertrophy resulting in compression of the conus medullaris and cauda equina. Decompressive surgery was successful in reversing some of his deficits.