brainstem atrophy

Kufor-Rakeb Syndrome

Clinical Characteristics
Ocular Features: 

Most patients have a supranuclear gaze paresis.  Patients later may have dystonic oculogyric spasms.

Systemic Features: 

This is a rapidly progressive neurodegenerative disorder with juvenile onset.  First signs of Parkinisonism are evident between the ages of 12 and 16 years of age.  Within a year of onset severe motor handicaps develop along with some degree of dementia with aggression and visual hallucinations.  Cognitive decline is often a feature.  Fine tremors in the chin may be seen along with other extrapyramidal signs but these are not prominent in the limbs.  Instead there is often rigidity and bradykinesia.  Dysphagia, dysarthria, and ataxia are features in many patients.  Peripheral sensory neuropathy and anosmia are present in some individuals. 

Brain imaging often reveals generalized atrophy of the cerebellum, cerebral cortex, and brainstem.

Genetics

This condition results from homozygous or compound heterozygous mutations in the ATP13A2 gene (1p36.13).  

Biallelic mutations in the same gene are also responsible for spastic paraplegia 78 (617225) with somewhat similar clinical features except for the general absence of Parkinsonism.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

There may be an initial therapeutic response to L-DOPA but this is often not maintained

References
Article Title: 

Loss-of-function mutations in the ATP13A2/PARK9 gene cause complicated hereditary spastic paraplegia (SPG78)

Estrada-Cuzcano A, Martin S, Chamova T, Synofzik M, Timmann D, Holemans T, Andreeva A, Reichbauer J, De Rycke R, Chang DI, van Veen S, Samuel J, Schols L, Poppel T, Mollerup Sorensen D, Asselbergh B, Klein C, Zuchner S, Jordanova A, Vangheluwe P, Tournev I, Schule R. Loss-of-function mutations in the ATP13A2/PARK9 gene cause complicated hereditary spastic paraplegia (SPG78). Brain. 2017 Feb;140(Pt 2):287-305.

PubMed ID: 
28137957

PEHO Syndrome

Clinical Characteristics
Ocular Features: 

Optic atrophy is a common feature.  There may be lack of visual fixation from birth or sometimes several months later, attributed to cortical inattention.  Flash visual evoked potentials may be unrecordable. Pupillary responses to light are 'weak' and sluggish. Epicanthal folds may be seen.

Systemic Features: 

Infants are usually born with a normal head circumference but fall behind (2 SD or more) in the first year.  They have neonatal and infantile central hypotonia with brisk peripheral tendon reflexes during early childhood.  They are sometimes described as drowsy or lethargic.  Facial and limb edema can be extensive but transient sometimes and can disappear later in childhood.  The fingers are tapered.  The cheeks are full, the mouth is usually open and the upper lip appears 'tented'.  Global developmental delay is common and normal milestones are seldom attained.  Some patients have been described as severely retarded mentally.  Infantile spasms and myoclonic jerkingcan be seen within the first months of life while frank seizures with hypsarrhythmia are common in the first year of life.  Status epilepticus is a common occurrence.  General drowsiness and poor feeding are often features.  Death usually occurs in infancy or early childhood.  Midface hypoplasia and micrognathia are often present.

Brain imaging (MRI) and histology show severe alterations in myelination and cellular organization.  Neuronal loss is seen in the inner granular layer of the cerebellum but there is relative preservation of Purkinje cells.  General and progressive atrophy of the cerebellum and brain stem have been described.

Genetics

Homozygous frameshift mutations in ZNHIT3 (17q12) have been identified in affected members of several consanguineous families.  The presumed mutation seems to be most prevalent in Finland.

A somewhat similar disorder known as PEHO-like syndrome (617507) is the result of homozygous mutations in the CCDC88A gene.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Physical therapy to prevent contractures and general supportive care can be helpful.  Supplemental feeding may be required. 

References
Article Title: 

The PEHO syndrome

Riikonen R. The PEHO syndrome. Brain Dev. 2001 Nov;23(7):765-9. Review.

PubMed ID: 
11701291

Microphthalmia, Syndromic 10

Clinical Characteristics
Ocular Features: 

Microphthalmia seems to be a common feature.  The globes have anterior-posterior dimensions of 5-8 mm.  No internal ocular structures can be visualized and individuals are likely blind.  The corneal diameters in two patients were measured at 3-4 mm.  The optic nerves have been described as ‘slender’ on brain imaging.

Systemic Features: 

Head circumference ranges from the 10th to the 25th percentile at birth  Psychomotor development has been described as normal during the first 6 to 8 months but is followed by rapid deterioration in performance with spasticity, vomiting and continuous crying.  An MRI on one 3 day old patient was reported as normal while at 15 months of age there was atrophy of the vermis and corpus callosum and at 8 years of age the atrophy of these structures was even more extensive.  Similar atrophy patterns were seen in the two other patients and eventually all cerebral while matter is lost and there is atrophy of the brainstem as well. 

Genetics

Three children from 3 consanguineous Pakistani families have been reported but no locus or mutation has been identified.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 
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