With the ICD 9 codes 2011 going into effect on October 1, 2010, as a neurology coder, you too can expect some changes likely to affect your practice. Here are some guidelines that will stand you in good stead:
Check your terminology
Patients and practitioners sometimes use the terms 'stroke' and 'CVA' interchangeably to refer to a cerebral infarction. The terms 'stroke', 'CVA and 'cerebral infarction NOS' each fall under diagnosis 434.91. The updated guidelines add, 'additional codes should be assigned for any neurological deficits with the acute CVA, irrespective of whether or not the neurologic defect resolves before discharge'.
Do not mix late effects with neurological deficits
Diagnoses under ICD-9's category 438 deal with late effects of cardiovascular disease. A late effect is the residual effect post the acute phase of an illness or injury has terminated. There is in fact, no time limit on when you can use a late effect code.
According to ICD 9 2010 guidelines, you needed to turn to 438.xx when indicating conditions in categories 430-437 as the cases of late effects. These late effects include neurological deficits that persist after the initial onset of conditions in categories 430-437, like speech and language deficits (438.1x), dysphagia (438.82), or vertigo (438.85).
With effect from October 1, 2010, guidelines specify to use codes in category 438 only for late effects of cerebrovascular disease, not for neurological deficits associated with an acute CVA.
Diagnosis signals disease
Guidelines under Section 1 C.18.d.3 differentiate status and history diagnosis codes.