Frequency and type of neurological manifestations
A total of 35 patients were included during the study period with a median age of 66 years (range, 20–93) and a clear male predominance (71%). The clinical and demographics data are shown in Table 1. The diagnosis of SARS-CoV-2 infection was made by pulmonary imaging (Rx or CT scan) in 7 patients and nasopharyngeal RT-PCR plus imaging in 28. There were no significant differences in the means of diagnosis across groups.
Table 1 Clinical and demographic characteristics of the patients Nineteen patients had been hospitalized for COVID-19 pneumonia and developed neurological problems during the period of hospitalization; 14 patients presented with a neurological disorder on admission which led to the diagnosis of COVID-19. Two patients consulted for a neurological complaint after discharge for COVID-19 (mild infection without pneumonia) and returned to the hospital on their own (1 anosmia and 1 peripheral neuropathy).
Thirty-one patients had radiologic evidence of SARS-CoV-2 pneumonia, and 4 patients had SARS-CoV-2 infection without pneumonia. Seventy-four percent (26/35) of the patients had a prior history of cardiovascular risk factors, particularly hypertension, 26% (9/35) had cardiovascular comorbidities, and 23% (8/35) had pulmonary comorbidities. Forty percent (14/35) had some neurological comorbidity.
Table 2 shows the neurological disorders that led to a neurological consultation, and whether they were the reason for admission or developed during hospitalization. The single most frequent reason was stroke (11 patients; the reason for admission in 4 patients and developed during the hospitalization period in 7 patients).
Table 2 Reasons for neurological consultation Of the 11 stroke patients, 8 had large vessel occlusion (5 middle cerebral artery, 2 carotid artery, and 2 vertebrobasilar system). Two patients presented a lacunar syndrome with a normal brain CT scan (MRI was not performed), and 1 patient had an arterial hemorrhage in the left cerebral hemisphere. There were no TIA cases. Two stroke patients died during hospitalization, both with a large vessel anterior circulation ischemic stroke. Four patients were subjected to mechanical thrombectomy with complete recanalization; 2 of them showed a significant improvement with a decrease > 4 points in the NIHSS, 1 without improvement (futile recanalization), and 1 without improvement due to a hemorrhagic transformation (vertebrobasilar stroke).
Encephalopathy (7 patients, defined as impaired attention and arousal, presenting with confusion, lethargy, delirium, or coma) followed in frequency and developed while the patients were hospitalized. All had a compromised respiratory function with hypoxemia, and 4 had a moderate increase in liver enzymes. One patient developed a refractory motor focal status epilepticus and finally died. The rest of the patients improved upon the restoration of their respiratory function.
Seizures developed in 6 patients and in 2 of them led to the diagnosis of COVID-19. All were de novo seizures except for 1 patient with a hypothalamic hamartoma and refractory gelastic seizures; he was in a poor previous condition, was institutionalized, and ultimately died from respiratory failure. Two patients had generalized tonic-clonic seizures that were controlled with IV levetiracetam. One patient had a non-convulsive status epilepticus (frontal origin) that resolved with an IV combination of levetiracetam and valproate. One patient with motor focal seizures died due to respiratory insufficiency. One patient had one episode consistent with seizures that did not require therapy and did not recur.
A brain CT scan was performed in all encephalopathy and seizure patients without any relevant findings.
Cranial or peripheral neuropathy was the reason for admission in 5 patients (14%), one of them with bilateral facial palsy. One patient with acute inflammatory demyelinating disease (AIDP) improved with IV immunoglobulin therapy. One patient with facial diplegia improved spontaneously as did one patient with VI nerve and another with VII nerve palsy.
Less common reasons for consultation developed during admission and included 2 non-convulsive syncope, 1 severe migraine attack in a migraineur, 1 isolated anosmia, 1 critical illness myopathy, and exacerbation of residual dysarthria in a patient with a history of stroke.
Ten patients were hospitalized in the ICU: 3 ischemic stroke patients (2 large vessel anterior circulation and 1 vertebrobasilar with hemorrhagic transformation after mechanical thrombectomy), 1 patient with status epilepticus, 5 encephalopathies, and 1 patient with critically illness myopathy.
Associations between clinical manifestations and variables of the study (Table 3)
Male gender predominated except for neuropathies. Stroke patients were significantly older, with a median age of 77, in comparison with 64 of seizure patients, 65 of encephalopathy, and 55 of neuropathy patients (p = 0.0033). Cardiovascular risk factors and cardiovascular and pulmonary comorbidities were particularly frequent among patients with stroke, seizures, and encephalopathy and less so in neuropathy patients with no statistically significant differences among groups (p = 0.1521).
Table 3 Comparative of patients’ characteristics according to the most common neurological consultation groups There was a lag between COVID-19 onset and the development of neurological complications that ranged from a median of 9 days (stroke) to 17 days (seizures).
As for disease severity, peripheral neuropathies occurred in patients with past or mild infection, whereas stroke, seizures, and encephalopathies developed in patients with SARS-CoV-2 pneumonia without statistically significant between-group differences in the CURB-65 score (p = 0.1756).
Some patients had more than one neurological complication: 3 of 10 stroke patients and 5 of 8 with seizures developed encephalopathy throughout the period of hospitalization, and 2 of 7 patients who presented with encephalopathy developed seizures during admission.
Among other neurological symptoms now typically associated with COVID-19, 6 patients also had anosmia, 4 migraines (3 of whom were prior migraineurs), and 4 myalgias. These were not the reason for consultation, except for 1 patient with anosmia.
Associations of laboratory values with clinical conditions
The evaluation of analytical parameters revealed an increase in CRP in all groups, particularly in stroke patients (Table 4). Another inflammatory marker, ferritin, was particularly increased in encephalopathy patients (median value of 1101 ng/ml) and less so in stroke (481 ng/ml) and seizure (949 ng/ml) patients; it was normal in neuropathy patients (137 ng/ml). Interestingly, D-dimer was increased in encephalopathy (median value 6170 ng/ml) patients at a higher level than in stroke (2400 ng/ml) or seizure (2100 ng/ml) patients; it was only slightly increased in patients with neuropathy (725 ng/ml). The coagulation parameters were within normal limits, including stroke patients. None of these parameters reached a between-group statistically significant difference.
Table 4 Analytical parameters for groups of most common neurological consultations An increase in creatinine levels was present in 2 stroke patients, 3 seizures, and 3 encephalopathies. Mild hypertransaminemia (less than three times normal) was present in 2 stroke patients, 4 seizures, 4 encephalopathies, and 2 neuropathies. Increased CK levels were present in 1 stroke, 1 seizure, 2 encephalopathies, and 1 neuropathy.
RT-PCR was performed in 8 CSF samples and was negative in all: 5 seizures, 1 syncope, 1 encephalopathy, and 1 patient with facial diplegia.
The influence of COVID-19 on stroke incidence and severity
During the same period of the study in 2019, a total of 123 stroke patients were admitted to our department, in contrast to 87 patients in 2020 (Table 5). The mean age was slightly higher in 2019 (74.53 vs. 72.31 years, p = 0.24), and stroke severity was significantly lower in 2019 (NIHSS 4.8 vs. 7.0, p = 0.027). The severity of the 11 strokes during the pandemic was not different from that of the total of patients admitted in the same period of 2020 (Table 5).
Table 5 Stroke incidence and severity during the study period of 2020 compared with 2019 NIHSS (National Institutes of Health Stroke Scale)