Expanded phenotype in a patient with spastic paraplegia 7

SPG7 and movement disorders: beyond the spastic paraplegia

Background

Spastic paraplegia type 7 (SPG7) mutations can present either as a pure form or a complex phenotype with movement disorders.

Objective

Describe the main features of subjects with SPG7 mutations associated with movement disorders.

Methods

We analyzed the clinical and paraclinical information of subjects with SPG7 mutations associated with movement disorders.

Results

Sixteen affected subjects from 11 families were identified. Male sex predominated (10 of 16) and the mean age at onset was 41.25 ± 16.1 years. A cerebellar syndrome was the most frequent clinical movement disorder phenotype (7 of 16); however, parkinsonism (2 of 16), dystonia (1 of 16), and mixed phenotypes between them were also seen. The "ears of the lynx" sign was found in four subjects. A total of nine SPG7 variants were found, of which the most frequent was the c.1529C > T (p.Ala510Val).

Conclusion

This case series expands the motor phenotype associated with SPG7 mutations. Clinicians must consider this entity in single or familial cases with combined movement disorders.

Palatal Tremor - Pathophysiology, Clinical Features, Investigations, Management and Future Challenges

Background:

Palatal tremor is involuntary, rhythmic and oscillatory movement of the soft palate. Palatal tremor can be classified into three subtypes; essential, symptomatic and palatal tremor associated with progressive ataxia.

Methods:

A thorough Pubmed search was conducted to look for the original articles, reviews, letters to editor, case reports, and teaching neuroimages, with the keywords “essential”, “symptomatic palatal tremor”, “myoclonus”, “ataxia”, “hypertrophic”, “olivary” and “degeneration”.

Results:

Essential palatal tremor is due to contraction of the tensor veli palatini muscle, supplied by the 5^th cranial nerve. Symptomatic palatal tremor occurs due to the contraction of the levator veli palatini muscle, supplied by the 9%^th and 10%^th cranial nerves. Essential palatal tremor is idiopathic, while symptomatic palatal tremor occurs due to infarction, bleed or tumor within the Guillain-Mollaret triangle. Progressive ataxia and palatal tremor can be familial or idiopathic. Symptomatic palatal tremor and sporadic progressive ataxia with palatal tremor show signal changes in inferior olive of medulla in magnetic resonance imaging. The treatment options available for essential palatal tremor are clonazepam, lamotrigine, sodium valproate, flunarizine and botulinum toxin. The treatment of symptomatic palatal tremor involves the treatment of the underlying cause.

Discussion:

Further studies are required to understand the cause and pathophysiology of Essential palatal tremor and progressive ataxia and palatal tremor. Similarly, the link between tauopathy and palatal tremor associated progressive ataxia needs to be explored further. Oscillopsia and progressive ataxia are more debilitating than palatal tremor and needs new treatment approaches.

[Common forms of hereditary spastic paraplegias]

A group of hereditary spastic paraplegias includes about 80 spastic paraplegia genes (SPG): forms with identified (almost 70) or only mapped (about 10) genes. Methods of next generation sequencing (NGS), along with new SPG discovering, modify knowledge about earlier delineated SPG. Clinical and genetic characteristics of common autosomal dominant (SPG4, SPG3, SPG31) and autosomal recessive (SPG11, SPG7, SPG15) forms are presented.

A Treatable Rare Cause of Progressive Ataxia and Palatal Tremor

Background

Cerebrotendinous xanthomatosis is a rare autosomal recessive neurometabolic disorder characterized by chronic diarrhea, tendon xanthomas, juvenile cataracts, and neurological symptoms.

Case Report

An adult patient with cerebrotendinous xanthomatosis exhibited ataxia and palatal tremor in the absence of tendon xanthomas and cataracts.

Discussion

The importance of this case resides on the fact that cerebrotendinous xanthomatosis should be considered as a possible etiology of the syndrome of progressive ataxia with palatal tremor, even in the absence of tendon xanthomas and cataracts. Early diagnosis is critical to the institution of specific treatment with chenodeoxycholic acid.

Expanded phenotype in a patient with spastic paraplegia 7

Hereditary spastic paraplegia is a group of clinically and genetically heterogeneous neurodegenerative disorders, often characterized by weakness and spasticity in the lower limbs. In our study, we describe a spastic paraplegia type 7 patient with an expanded phenotype who was diagnosed after the discovery of pathogenic variants in SPG7.