Complex sentence: When he finally emerged in the spring of 1948, his hygiene was terrible, he had not bathed nor cut his hair and nails for weeks although this may have been due to allodynia (pain response to stimuli that would normally not cause pain).
Split into simpler sentences: When he finally emerged in the spring of 1948, his hygiene was terrible. He had not bathed nor cut his hair and nails for weeks, although this may have been due to allodynia (pain response to stimuli that would normally not cause pain).