Belhocine Ouardia, André Christine, Kalifa Gabriel, Adamsbaum Catherine
Radiology Department, St Vincent de Paul Hospital, 82 avenue Denfert-Rochereau, 75674 Paris, France.
Pediatr Radiol. 2005 Apr;35(4):410-8. doi: 10.1007/s00247-004-1378-2. Epub 2005 Feb 15.
Primary septal agenesis (PSA) is a rare brain malformation that can be isolated or part of developmental brain abnormalities (holoprosencephaly, septo-optic dysplasia or cortical malformation). Such associated malformation can be subtle, leading to difficulties in the prenatal management of PSA. Moreover, the neurological prognosis of isolated PSA remains debatable.
The aims of the study were to specify the patterns and frequency of brain malformations associated with septal agenesis (SA), to identify the clinical prognosis, and to discuss the aetiology of PSA with the new insights provided by molecular genetics.
The study consisted of a 14-year retrospective review of brain MRI in 34 patients having PSA (mean age, 5 years). Chiasm and optic nerves were not evaluated. Post-hydrocephalus SA or incomplete data were excluded. The clinical data were correlated to the MRI patterns.
The study disclosed 82.5% associated lesions with MRI (28/34): 11 neuronal migration disorders, 9 holoprosencephalies (HP), 7 pituitary stalk interruptions, 1 corpus callosum partial agenesis; 17.5% (6/34) of cases were apparently isolated PAS. Clinically, the patients had motor dysfunction in 68% (23/34), mental retardation in 65% (22/34), blindness in 24% (8/34), endocrinological defects in 21% (7/34) and epilepsy in 18% (6/34) of cases. Nine percent of patients (3/34) were neurologically normal (including one with scoliosis and two infants younger than 2 years at the last follow-up). Patients with bilateral cortical anomalies and HP (even if mild) had the worst neurological prognosis. A severe motor impairment was present without evidence of hemispheric anomaly in 12% of patients (4/34). Interestingly, the frontal lobes were involved in 90% of cortical anomalies and HP, supporting the malformative aetiology of PSA.
PSA rarely appears isolated and severe psychomotor impairment may occur in apparently isolated forms. These unfavourable results should be highlighted and need to be confirmed by a prospective study.
原发性中隔发育不全（PSA）是一种罕见的脑畸形，可为孤立性或作为脑发育异常（全前脑畸形、视隔发育不良或皮质畸形）的一部分。这种相关畸形可能很细微，导致PSA产前管理存在困难。此外，孤立性PSA的神经学预后仍有争议。
本研究的目的是明确与中隔发育不全（SA）相关的脑畸形模式和频率，确定临床预后，并结合分子遗传学提供的新见解讨论PSA的病因。
本研究对34例PSA患者（平均年龄5岁）进行了为期14年的脑部MRI回顾性分析。未评估视交叉和视神经。排除脑积水后SA或数据不完整的病例。将临床数据与MRI模式相关联。
研究发现82.5%的患者MRI存在相关病变（28/34）：11例神经元迁移障碍、9例全前脑畸形（HP）、7例垂体柄中断、1例胼胝体部分发育不全；17.5%（6/34）的病例为明显孤立性PSA。临床上，68%（23/34）的患者有运动功能障碍，65%（22/34）的患者有智力障碍，24%（8/34）的患者失明，21%（7/34）的患者有内分泌缺陷，18%（6/34）的患者有癫痫。9%的患者（3/34）神经功能正常（包括1例脊柱侧弯患者和2例末次随访时年龄小于2岁的婴儿）。双侧皮质异常和HP患者（即使较轻）神经学预后最差。12%的患者（4/34）存在严重运动障碍但无半球异常证据。有趣的是，90%的皮质异常和HP累及额叶，支持PSA的畸形病因。
PSA很少单独出现，明显孤立形式也可能发生严重精神运动障碍。这些不良结果应予以强调，需要前瞻性研究予以证实。
