Reconsideration of the classification of the neuronal ceroid-lipofuscinoses

Neuronal ceroid-lipofuscinoses (NCL) represent diseases of different types. Each variety of NCL may have its own clinical course, genetics, pathogenesis, and treatment. Four disorders are presently accepted as examples of NCL. These include the chronic juvenile or Batten type, the acute late infantile or Bielschowsky type, the chronic or subacute adult Kufs type, and the acute infantile or Santavuori-Haltia type. Seventy patients with clinical and pathological features of NCL have been studied over 20 years; 62 of these fit into one of the above categories, but 8 are atypical and present nosologic problems. Recognized as examples of atypical NCL are 1) chronic congenital or Norman-Wood type, 2) acute adult or Zeman-Dyken type, 3) acute childhood or Bielschowsky variant, 4) chronic childhood (Edathodu-Dyken) type, with pervasiveness, 5) chronic infantile (Dyken) type with autism, and 6) chronic juvenile (Dyken) type with ataxia. It is proposed that our present classification of NCL be based on differentiating clinical dynamics and characteristics, age-of-onset, and morphological and pathological criteria. Although genetic characteristics are now recognized, these are of autosomal recessive or autosomal dominant type. No differentiating biochemical differences have been established to aid in the nosology of these diseases.