Cerebellar ataxia with sensory ganglionopathy; does autoimmunity have a role to play?

Background and purpose: Cerebellar ataxia with sensory ganglionopathy (SG) is a disabling combination of neurological dysfunction usually seen as part of some hereditary ataxias. However, patients may present with this combination without a genetic cause. Methods: We reviewed records of all patients that have been referred to the Sheffield Ataxia Centre who had neurophysiological and imaging data suggestive of SG and cerebellar ataxia respectively. We excluded patients with Friedreich's ataxia, a common cause of this combination. All patients were screened for genetic causes and underwent extensive investigations. Results: We identified 40 patients (45% males, mean age at symptom onset 53.7 ± 14.7 years) with combined cerebellar ataxia and SG. The majority of patients (40%) were initially diagnosed with cerebellar dysfunction and 30% were initially diagnosed with SG. For 30% the two diagnoses were made at the same time. The mean latency between the two diagnoses was 6.5 ± 8.9 years (range 0-44). The commonest initial manifestation was unsteadiness (77.5%) followed by patchy sensory loss (17.5%) and peripheral neuropathic pain (5%).Nineteen patients (47.5%) had gluten sensitivity, of whom 3 patients (7.5%) had biopsy proven coeliac disease. Other abnormal immunological tests were present in another 15 patients. Six patients had malignancy, which was diagnosed within 5 years of the neurological symptoms. Only 3 patients (7.5%) were classified as having a truly idiopathic combination of cerebellar ataxia with SG. Conclusion: Our case series highlights that amongst patients with the unusual combination of cerebellar ataxia and SG, immune pathogenesis plays a significant role

Axonal swellings predict the degeneration of epidermal nerve fibers in painful neuropathies

Objective: To correlate the density of swellings in intraepidermal nerve fibers (IENF) with the longitudinal measurement of the epidermal innervation density in patients with painful neuropathy and to assess the predictive value of IENF swelling to progression of neuropathy. Methods: Fifteen patients with persistent pain in the feet underwent neurologic examination, nerve conduction studies, quantitative sensory examination, and skin biopsies at proximal thigh and distal leg. In all patients and in 15 healthy subjects, IENF density and swelling ratio (no. swellings/no. IENF) were quantified at distal leg. Follow-up study, including IENF density and swelling ratio quantification, was performed a mean of 19.2 months later. Double staining confocal microscope studies using anti-human protein-gene-product 9.5, anti-tubule, anti-neurofilament, and anti-synaptophysin antibodies were performed to assess specific accumulation within swellings. Ultrastructural investigation of IENF was also carried out. Results: Patients with neuropathy had lower density of IENF and higher swelling ratio than healthy subjects (p<0.01) at distal leg. At follow-up, patients showed a parallel decrease in both IENF density (p=0.02) and swelling ratio (p=0.002). However, swelling ratio remained higher (p=0.03) than in controls. Progression of neuropathy was confirmed by the decay in sural nerve sensory nerve action potential amplitude. Double immunostaining studies suggest accumulation of tubules and ubiquitin-associated proteins within swellings. Swollen and vacuolated IENF were identified in patients with neuropathy by conventional and immuno-electron microscopy. Conclusions: Increased swelling ratio predicted the decrease in IENF density in patients with painful neuropathy. Its quantification could support earlier diagnosis of sensory axonopathy

Cerebellar ataxia and sensory ganglionopathy associated with light-chain myeloma.

BACKGROUND: Cerebellar ataxia with sensory ganglionopathy is a rare neurological combination that can occur in some hereditary ataxias including mitochondrial diseases and in gluten sensitivity. Individually each condition can be a classic paraneoplastic neurological syndrome. We report a patient with this combination who was diagnosed with light-chain myeloma ten years after initial presentation. CASE PRESENTATION: A 65-year-old Caucasian lady was referred to our Ataxia Clinic because of a 6-year history of progressive unsteadiness and a 2-year history of slurred speech. Past medical history included arterial hypertension. The patient was a non-smoker was not consuming alcohol excessively. There was no family history of ataxia. Neurological examination revealed prominent gaze-evoked nystagmus, heel to shin ataxia, gait ataxia, reduced reflexes and loss of vibration sensation in the legs. Cerebellar ataxia was confirmed using magnetic resonance spectroscopy of the cerebellum and sensory ganglionopathy using neurophysiological assessments including blink reflex study. A muscle biopsy that was arranged to explore the possibility of mitochondrial disease revealed amyloidosis. Urinalysis confirmed the presence of light chains. A bone marrow biopsy confirmed the diagnosis of light chain multiple myeloma. CONCLUSIONS: Whilst it could be argued that this could simply be a coincidence, the rarity of these conditions and the absence of an alternative aetiology for the neurological dysfunction argue in favour of a paraneoplastic phenomenon

Cranial nerve involvement in CMT disease type 1 due to early growth response 2 gene mutation

Mutations in the gene coding for the Schwann cell transcription factor early growth response 2 (EGR2), which seems to regulate myelinogenesis and hindbrain development, have been observed in few cases of inherited neuropathy. The authors describe a unique combination of cranial nerve deficits in one member of a Charcot-Marie-Tooth 1 family carrying an EGR2 mutation (Arg381His). This finding further supports the role of EGR2 in cranial nerve development

Myasthenia gravis

Myasthenia gravis (MG) is a rare, autoimmune neuromuscular junction disorder. Contemporary prevalence rates approach 1/5,000. MG presents with painless, fluctuating, fatigable weakness involving specific muscle groups. Ocular weakness with asymmetric ptosis and binocular diplopia is the most typical initial presentation, while early or isolated oropharyngeal or limb weakness is less common. The course is variable, and most patients with initial ocular weakness develop bulbar or limb weakness within three years of initial symptom onset. MG results from antibody-mediated, T cell-dependent immunologic attack on the endplate region of the postsynaptic membrane. In patients with fatigable muscle weakness, the diagnosis of MG is supported by: 1. pharmacologic testing with edrophonium chloride that elicits unequivocal improvement in strength; 2. electrophysiologic testing with repetitive nerve stimulation (RNS) studies and/or single-fiber electromyography (SFEMG) that demonstrates a primary postsynaptic neuromuscular junctional disorder; and 3. serologic demonstration of acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK) antibodies. Differential diagnosis includes congenital myasthenic syndromes, Lambert Eaton syndrome, botulism, organophosphate intoxication, mitochondrial disorders involving progressive external ophthalmoplegia, acute inflammatory demyelinating polyradiculoneuropathy (AIDP), motor neuron disease, and brainstem ischemia. Treatment must be individualized, and may include symptomatic treatment with cholinesterase inhibitors and immune modulation with corticosteroids, azathioprine, cyclosporine, and mycophenolate mofetil. Rapid, temporary improvement may be achieved for myasthenic crises and exacerbations with plasma exchange (PEX) or intravenous immunoglobulin (IVIg). Owing to improved diagnostic testing, immunotherapy, and intensive care, the contemporary prognosis is favorable with less than five percent mortality and nearly normal life expectancy

Autoimmune Neuromuscular Disorders in Childhood

Autoimmune neuromuscular disorders in childhood include Guillain-Barré syndrome and its variants, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), juvenile myasthenia gravis (JMG), and juvenile dermatomyositis (JDM), along with other disorders rarely seen in childhood. In general, these diseases have not been studied as extensively as they have been in adults. Thus, treatment protocols for these diseases in pediatrics are often based on adult practice, but despite the similarities in disease processes, the most widely used treatments have different effects in children. For example, some of the side effects of chronic steroid use, including linear growth deceleration, bone demineralization, and chronic weight issues, are more consequential in children than in adults. Although steroids remain a cornerstone of therapy in JDM and are useful in many cases of CIDP and JMG, other immunomodulatory therapies with similar efficacy may be used more frequently in some children to avoid these long-term sequelae. Steroids are less expensive than most other therapies, but chronic steroid therapy in childhood may lead to significant and costly medical complications. Another example is plasma exchange. This treatment modality presents challenges in pediatrics, as younger children require central venous access for this therapy. However, in older children and adolescents, plasma exchange is often feasible via peripheral venous access, making this treatment more accessible than might be expected in this age group. Intravenous immunoglobulin also is beneficial in several of these disorders, but its high cost may present barriers to its use in the future. Newer steroid-sparing immunomodulatory agents, such as azathioprine, tacrolimus, mycophenolate mofetil, and rituximab, have not been studied extensively in children. They show promising results from case reports and retrospective cohort studies, but there is a need for comparative studies looking at their relative efficacy, tolerability, and long-term adverse effects (including secondary malignancy) in children