Table 3.
Quantitative criteria for diagnosis of LM.
| Diagnostic factors | Score |
|---|---|
| History of malignancy | 0~1 |
| No | 0 |
| Yes | 1 |
| Clinical manifestations a | 0~2 |
| None | 0 |
| Single symptom in cerebral hemisphere, cranial nerve, or spinal nerves | 1 |
| Typical LM-related symptoms or signsb | 2 |
| Neuroimaging findings c | 0~4 |
| Normal | 0 |
| Suggestive featuresd | 1 |
| Diagnostic featurese | 4 |
| CSF cytology f | 0~5 |
| Negative | 0 |
| Suspicious malignant cells | 3 |
| Malignant cells | 5 |
| Aberrant CSF biochemical analysis g | 0~1 |
| Normal | 0 |
| Abnormal | 1 |
For each patient, a history of malignancy was firstly checked, followed by nuerological examination and neuroimaging examination. Patients with a score of ≥3 should be suggested to receiving CSF examination, and those with a score of ≥5 were confirmed with LM.
After neurological examination, nueroimaging and CSF examination, further examination or review was needed for those with a score of ≤3. Those with a score of 4 were suspicious with LM, and diagnostic treatment for LM (i.e. intrathecal chemotherapy) should be given if the antidiastole (i.e. subarachnoid blood, infection or inflammation) has been excluded. The patients were validated with LM upon remission of the neurological symptoms/signs after diagnostic treatment.
aOther conditions that may induced the symptoms should be excluded such as infectious diseases. For patients with symptoms in nerve roots, intervertebral disk degeneration should be excluded. For patients with headache, brain metastasis with obvious space-occupying lesions in MRI or trigeminal neuralgia should be excluded.
bNeurological deficits were severe and progressively deteriorative or in multiple sites. Multiple neurological deficits implied disseminated involvement of CNS.
cSuch features should be confirmed by specialists. Patients simultaneously with diagnostic and suggestive neuroimaging features were bequeathed a score of 4.
dSuggestive features included metastatic lesions approaching subarachnoid space, enhancement in dura mater, metastatic lesions approaching ventricles, enhancement in cranial nerves, and communicating hydrocephalus.
eDiagnostic features included enhancement in leptomeninges and ependyma, as well as implantation metastases in vertebral canal and ventricles. Any irritation of the leptomeninges (e.g. subarachnoid blood, infection and inflammation) can result in enhancement on MRI. Therefore, these diseases should be excluded.
fA volume of ≥10.5 ml was recommended for the CSF sample collection. The samples should be submitted for analysis within 30 minutes.
gAberrant CSF results included elevation of white blood cells and protein(>0.45 g/L), and decrease of glucose(<2.8 mmol/L).