Relationship between nailfold plexus visibility and clinical, neuropsychological, and brain structural measures in schizophrenia.

BACKGROUND: Although all published studies investigating the association between nailfold plexus visibility and schizophrenia have found the subpapillary plexus (the vascular network into which capillaries drain) to be unusually visible in many schizophrenia patients, little else is known about this putative marker for schizophrenia liability.
METHODS: Plexus visibility was rated in 63 chronic schizophrenia, 67 first-episode schizophrenia, 9 schizophreniform, and 66 unipolar and bipolar depressed patients, all with psychosis, and 119 nonpsychiatric controls. Smooth-pursuit eye tracking, clinical features, neuropsychological performance, and lateral ventricle size were assessed.
RESULTS: Approximately 21% of chronic schizophrenia, 22% of first-episode schizophrenia, and 22% of schizophreniform patients had highly visible plexus compared to only 8% of unipolar, bipolar, and nonpsychiatric controls. Schizophrenia patients with visible plexus had worse oculomotor performance. Additionally, chronic schizophrenia patients with visible plexus had more negative symptoms, worse course, more severe illness, worse occupational functioning, and worse neuropsychological performance on tasks thought to be sensitive to frontal dysfunction. An inverse relationship between plexus visibility and lateral ventricle size was found.
CONCLUSIONS: This study provides evidence that schizophrenia patients with plexus visibility are characterized by oculomotor dysfunction, negative symptoms, severe symptomatology, chronic course, neuropsychological dysfunction, and an absence of enlarged ventricles.