Fahr病

CT像で見られる頭蓋内の生理学的石灰化の部位は，脈絡叢 ，松果体 ，手綱交連 ，大脳基底核 ，血管壁 ，大脳鎌・小脳テントである。これに対して，家族性特発性基底核石灰化症（familial idiopathic basal ganglia calcification：IBGC，Fahr病）は，両側対称性に大脳基底核や線状体基底核に石灰化を呈する疾患で，認知障害，ジストニア，パーキンソニズム，失調，行動異常などの症状を呈する。1分～2分の意識消失で搬入されてきたものの，救急外来搬入時に今一つ意識ははっきりせず，CT像を評価した。このようCT像でIBGCが偶然見つけられることがあるようだ。IBGCの遺伝形式は常染色体優性遺伝形式であり，第14番染色体長腕に遺伝子座に連鎖することが知られている。舞踏病，Parkinson病，家族性めまいなどの原因のひとつとしても，IBGCは知られている。本症例の石灰化像は，大脳基底核，半卵円中心，皮質回転谷部，視床，小脳皮質，白質，歯状核に認められた。石灰化の進展に伴い癲癇が誘発された可能性にも留意しなければならない。


<文献1> Ogata A, Ishida S, Wada T.　A survey of 37 cases with basal ganglia calcification (BGC): CT-scan findings of BGC and its relationship to underlying diseases and epilepsy. Acta Neurol Scand. 1987;75:117-24.

Thirty-seven cases that showed bilateral basal ganglia calcification (BGC) were found in 5987 patients. These cases (0.6%) were studied in relation to their CT findings, underlying diseases and epilepsy. CT findings of BGC were divided into "localized" type (33 cases) and "diffuse" type (4 cases). The number of patients with the "localized" type clearly seemed to increase with age. The M:F ratio of the "localized" type was 1:2. The "localized" type was seen in both idiopathic BGC and familial BGC. The "diffuse" type was seen in hypoparathyroidism only. The specific relationship of these two types of BGC to underlying diseases, however, does not fully agree with results so far reported. We experienced a case with familial BGC during this study that appears to be only the 15th so far reported. Partial epilepsy occurred in 75% of epilepsy with BGC, but there seemed to be no direct relationship between BGC and epileptogenicity.


<文献2> Ostling S, Andreasson LA, Skoog I. Basal ganglia calcification and psychotic symptoms in the very old. Int J Geriatr Psychiatry. 2003;18:983-7.

BACKGROUND: Basal ganglia calcification (BGC) is associated with psychotic symptoms in young and middle-aged patient samples. METHODS: We studied the cross-sectional relationship between psychotic symptoms and BGC in a population sample of non-demented 85-year-olds, of whom 86 were mentally healthy, 11 had hallucinations or delusions, 21 had mood disorders and 20 had anxiety disorders. BGC was measured using computerized tomography (CT). Mental disorders were diagnosed using DSM-III-R criteria and psychotic symptoms were evaluated using information from psychiatric examinations, key-informant interviews and review medical records. RESULTS: BGC on CT was observed in 19% of mentally healthy and 64% of non-demented individuals with hallucinations or delusions [Odds Ratio (OR) 7.7, 95% Confidence Intervals (CI) 2.9-29.7, p=0.003]. There were no associations between BGC and mood or anxiety disorders. CONCLUSIONS: BGC is strongly associated with psychotic symptoms in very old age, possibly due to a disturbance in the basal ganglia dopaminergic system.