Answer: According to the ICD-9 manual, the correct code for generalized weakness is 780.79 (other malaise and fatigue), advises Catherine A. Brink, CMM, CPC, president of Healthcare Resources Management Inc., a practice management and reimbursement consulting firm in Spring Lake, N.J., that consults with several neurology practices. In the manual, this section of codes (780-799) includes symptoms, signs, abnormal results of laboratory or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded. Practically all categories in this group could be designated as not otherwise specified, or as unknown etiology, or as transient.
A not otherwise specified code can be a valid code if it most closely describes the diagnosis, but such codes should be used only after checking all other options. The Medicare carrier could deny the service rendered for lack of medical necessity based on the ICD-9 code attached to the CPT code. High-level evaluation and management (E/M) services often are denied on this basis. The neurologist should determine if there is a more specific diagnosis and/or other secondary diagnoses present for the service provided.
Also, individual Medicare carriers may have their own ICD-9 requirements for this condition, so the neurologist should check with his or her Medicare carrier to learn what code will be accepted.
Andrea Lamb, CPC, a billing specialist for St. Josephs Medical Plaza, a multispecialty practice in Jane Lew, W.Va., reports that other possible ICD-9 codes may be considered if the patient exhibits pronounced weakness in a particular area, such as the leg. Depending on the patients symptoms, ICD-9 codes that could be applicable include 344.30 (paralysis of lower limb, affecting unspecified side), 344.40 (paralysis of upper limb, affecting unspecified side) and 781.4 (transient paralysis of limb), which includes monoplegia.
Progressive generalized weakness also may be an indicator of Myasthenia gravis (358.0), a disorder involving neuromuscular strength that occurs during sustained or repetitive muscle contraction. It is a painless neuromuscular disease that is difficult to diagnose because patients may have normal muscle function at times, then experience a loss of strength at others. Most patients suffer generalized weakness within 13 weeks of clinical onset. Ocular symptoms may also be present, along with diplopia (368.2), dysarthria (784.5) or dysphagia (787.2).