Rw. Miller et al., A practice pathway for the initial diagnostic evaluation of isolated sixthcranial nerve palsies, MED DECIS M, 19(1), 1999, pp. 42-48
Purpose: To define a practice pathway for the evaluation of sixth-nerve pal
sies (SNPs) and to determine its cost-effectiveness and validity in a retro
spective chart review. Methods: A Medline search of the English-language li
terature from 1966 to 1995 was performed to define the available clinical e
vidence and develop the practice pathway. The authors retrospectively revie
wed 407 charts with the diagnosis of SNP seen at three centers. Information
obtained included: etiologic diagnosis if known; development of new neurol
ogic or ophthalmologic findings; and results and costs of neuroimaging stud
ies, if performed. Results: Of the 407 patients, 98 underwent computed tomo
graphy scans and 212 underwent magnetic resonance imaging of the head. Eigh
ty cases were non-isolated, 317 were isolated SNP, and ten could not be cla
ssified from chart information. Of the 317 cases of isolated SNP, 49 were c
lassified as traumatic; 5, congenital; 158, vasculopathic; 63, nonvasculopa
thic; and 42, progressive or unresolved. Following the recommendations of t
he practice pathway, the 158 patients classified as having vasculopathic SN
P would not have undergone neuroimaging studies, realizing a savings of $10
0,000 in this study population of 407 patients. Conclusion: The recommendat
ions of the practice pathway are supported by review of the literature and
the retrospective review of these cases. However, a prospective study with
a matched control group is needed to demonstrate regional and specialty-spe
cific variations in care and to strengthen the clinical certainty of the pa
thway recommendations.