What Is Fatal Familial Insomnia?

Chinese name: Fatal familial insomnia

Fatal familial insomnia

Chinese name: Fatal familial insomnia

English name: fatal familial insomnia

Alias: Fatal familial insomnia ^[1]

Basic overview of fatal familial insomnia

Fatal familial insomnia (FFI) is a recently recognized familial human prion disease. Characterized by insomnia.

PrP gene mutation

FFI is an autosomal dominant hereditary disease and is associated with the 129Met 178Asn haplotype. It has been confirmed that 17 FFI patients from 5 families without kinship have a mutation in the codon PRNP 178. Asn replaces (178Asn). In addition, the Met / Val polymorphism of codon 129 in the PRNP gene of FFI patients is also unevenly distributed. The distribution of this polymorphism in the normal Caucasian population is Met / Met 0.37, Met / Va10 .51, Va1 / Va10.12; while in FFI patients, it is Me / Met 0.82, Met / Val 0.18, Val / Va10. Further analysis also found that the 129 codons of the PRNP mutant allele in FFI patients are all Met.

Fatal familial insomnia symptoms

Generally speaking, there are three different manifestations at the beginning of the disease: sleep disorders, usually patients complain of insomnia, dreams during sleep; motor signs, such as dysarthria and ataxia; memory disorders. As the disease progresses, patients present with all the symptoms of FFI, involving motor, endocrine and autonomic nervous systems. details as follows:

1. Sleep and insomnia. Progressive insomnia. Insomnia is increasing in weight. This has been demonstrated in 8 patients in 4 families who underwent polysomnography or overnight EEG recordings. Treatment with hypnotic drugs such as diazepam and barbiturates was ineffective. The patient also showed progressive dream-like states and hallucinations, and was stiff and lethargic at the end of the illness.

2. Recognition function. Working memory, attention and visumotor function are impaired, but global intelligence is still maintained.

3. Patients with autonomic nervous system showed hyperhidrosis, tachycardia, fever, hypertension and irregular breathing.

4. Progressive weight gain of dyskinesia in the motor system until articulation is unclear and dysphagia, ataxia, spontaneous and excitatory myoclonus, hyperreflexia, and Babinski sign are present.

5. Adrenocorticotropic hormone (ACTH) levels are decreased in endocrine system. Cortisol and catecholamine levels are increased. Growth hormone, prolactin, and melatonin have abnormal 24h rhythm.

Fatal familial insomnia diagnosis

In 1993 Gambetti et al proposed the following diagnostic criteria:

1. Often stained and manifested disease, onset in adulthood, the course of 6 to 32 months.

2. Present intractable insomnia, familial autonomic dysfunction, memory disorders, ataxia, and / or myoclonic pyramidal and extrapyramidal signs

3.129Met and 178Asn haplotypes.

Differential diagnosis of fatal familial insomnia

In addition to fatal familial insomnia, sporadic fatal insomnia may also exist

In 1988, Mizusawa et al. Reported a case of sporadic lethal insomnia. The patient was 37 years old. Men have a history of insomnia, dementia, myoclonus, ataxia, nocturnal agitation, and autonomic dysfunction for 30 months before birth. Histopathological examination revealed severe anterior dorsal, medial dorsal, lateral dorsal and occipital nucleus atrophy, mild cortex edema in the cerebral cortex, scattered 'torpedoes' in the cerebellar cortex, and severe loss of olive neurons. In this case, PrPSC examination and PRNP gene analysis were performed. The PrPSC examination was positive, but PRNP was not mutated. From 1939 to 1975, Stem et al., Schulman et al., Garcin et al. And Martin et al. Reported some cases under the names of thalamic atrophy or thalamic CJD. These cases may also be sporadic lethal insomnia.