From the Guidelines
Albuminocytologic dissociation is defined as the presence of elevated cerebrospinal fluid (CSF) protein levels with a normal CSF cell count, a classic finding in Guillain-Barré syndrome (GBS) but also seen in other conditions. This dissociation occurs when the CSF protein level is elevated, typically above 45-50 mg/dL, while the white blood cell count remains normal, less than 5 cells/mm³, indicating a disruption of the blood-CSF barrier without inflammation or infection 1. The key differential diagnoses for albuminocytologic dissociation include:
- Guillain-Barré syndrome (GBS), the most common and classic cause
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Diabetic polyradiculopathy
- Spinal cord compression
- Multiple sclerosis
- Certain neoplastic conditions like carcinomatous meningitis Less common causes may involve sarcoidosis, HIV-related neuropathies, and specific metabolic disorders. It's crucial to interpret albuminocytologic dissociation in the context of the clinical presentation, considering the timing of the lumbar puncture, as protein elevation in GBS may not be evident until 1-2 weeks after symptom onset 1. The pathophysiology underlying this condition involves increased permeability of the blood-CSF barrier or reduced CSF flow and protein reabsorption, distinct from the inflammatory cell infiltration characteristic of infectious processes. In clinical practice, encountering albuminocytologic dissociation should prompt immediate consideration of GBS, especially in cases of acute ascending weakness and areflexia, or CIDP for more chronic symptoms.
From the Research
Definition of Albumino Cytological Dissociation
- Albumino cytological dissociation (ACD) is defined as an elevated cerebrospinal fluid (CSF) total protein level with a relatively low cell count, typically <50 cells/L 2, 3.
- The classic definition of ACD is a CSF-total protein (CSF-TP) >0.45 g/L with a cell count of <50 cells/L 3.
Differentials of Albumino Cytological Dissociation
- ACD can be seen in various conditions, including Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathies, and other forms of the GBS spectrum, such as axonal motor or motor-sensory forms (AMAN, AMSAN) 2.
- Other conditions that may present with ACD include Miller Fisher syndrome, Bickerstaff brainstem encephalitis, and polyneuropathy 2, 4.
- ACD can also be seen in patients with isolated headache, but the use of an age-adjusted upper reference limit for CSF-TP can help exclude these patients and improve diagnostic specificity 4.
Diagnostic Criteria and Age-Adjusted Reference Intervals
- The use of age-adjusted upper reference limits for CSF-TP can improve the diagnostic specificity of ACD and help avoid overdiagnosis 3, 4.
- Age-adjusted reference intervals can also help identify patients with "true" ACD, who are more likely to have a suitable diagnosis, such as polyneuropathy 4.
- The diagnostic criteria for ACD should take into account the patient's age, as well as other factors, such as the presence of other neurological symptoms and the results of electrophysiological studies 3, 4.