"Canavan disease is prevalent in the Ashkenazi Jewish community 1. The carrier frequency among the Ashkenazi ranges from 1:37 to 1:57, with a corresponding prevalence of 1 in 6000-14,000 in this high-risk group1. In the general population, the prevalence is 1 in 100,000 11."
"T1: areas of low signal"
"T2/FLAIR: findings as above except for areas of high signal in the affected white matter"
"DWI: restricted diffusion within the diseased white matter"
"MR spectroscopy: markedly elevated NAA and NAA:creatine ratio are pathognomonic for the condition 11."
"MR spectroscopy: markedly elevated NAA and NAA:creatine ratio are pathognomonic for the condition 11."
"It was first described by Myrtelle Canavan (1879-1953), an American neuropathologist, in her 1931 seminal paper 9,10."
"It is an autosomal recessive disorder due to a gene mutation on the short arm of chromosome 17 leading to deficiency of N-acetylaspartoacylase, a key enzyme in myelin synthesis, with resultant accumulation of N-acetylaspartate (NAA) in the brain, cerebrospinal fluid, plasma, and urine 3,4. Although its effects are widespread, it has a predilection for subcortical U-fibres and Alzheimer type II astrocytes in the gray matter 3,5."
"The oedematous sponginess of the white matter causes a characteristically low radiographic attenuation on CT so that it stands out from the relatively unaffected gray matter 4. Megalencephaly may also be also noted depending on the clinical stage 4."
"this can be remembered using the mnemonic CaNAAvan"
Expected headings
"Clinical features"
"There are a wide range of clinical features. Generally, there is a progression from lethargy and hypotonia, to macrocephaly (due to underlying megalencephaly) and spasticity, to blindness and seizures, to decerebrate posturing and eventual death 2. In the vast majority of patients, clinical onset is in infancy with death before 5 years of age, and often before 18 months, but juvenile-onset forms of the disease have also been reported 2. Juvenile-onset forms may have speech difficulty, mild intellectual impairment and suffer neurological regression 11."
"There is no enhancement of affected regions on either CT or MRI 5-8."
"It is an autosomal recessive disorder due to a gene mutation on the short arm of chromosome 17 leading to deficiency of N-acetylaspartoacylase, a key enzyme in myelin synthesis, with resultant accumulation of N-acetylaspartate (NAA) in the brain, cerebrospinal fluid, plasma, and urine 3,4. Although its effects are widespread, it has a predilection for subcortical U-fibres and Alzheimer type II astrocytes in the gray matter 3,5."
"generally with sparing of the corpus callosum, caudate nucleus, putamen and internal capsule"