Persistent dysarthria after cefazolin-induced status epilepticus

Brain Injury, September 2009; 23(10): 846–851

CASE STUDY

Persistent dysarthria after cefazolin-induced status epilepticus

YUNA LEE1, SUNG-BOM PYUN1, EUN KYUNG PARK2, & SUNG WON YOUN3 Department of Physical Medicine and Rehabilitation, 2Department of Nuclear Medicine, and 3Department of Radiology, Korea University College of Medicine, Seoul, South Korea

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(Received 26 December 2008; accepted 20 July 2009)

Abstract Background: Cefazolin is a well-known antibiotic associated with seizures. However, intrathecal cefazolin-induced status epilepticus (SE) is very rare and resultant persistent dysarthria has not been previously reported. Case report: A 66-year-old woman underwent epidural adhesiolysis due to lumbar spinal stenosis and 500 mg of cefazolin was infused through the thecal puncture site during the procedure. SE developed abruptly 40 minutes later and it persisted for 3 days. Severe dysarthria, dysphagia and cognitive dysfunction developed after the cessation of SE. Although the patient’s other symptoms showed much improvement after rehabilitation, the dysarthria did not improve after intense speech therapy for 8 months. The brain MRI showed no abnormal findings, but the 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) of the brain demonstrated hypometabolic areas in the bilateral inferior frontal gyrus and the primary motor cortex, representing the oromotor area. Conclusion: Although the exact mechanism underlying the dysarthria is unknown, the dysfunction of the inferior frontal network for speech production revealed by the brain FDG-PET, including the motor speech area (Broca’s area), left insula and bilateral primary and premotor cortex representing the oromotor area, might have been responsible for the persistent dysarthria in this patient. Keywords: Dysarthria, seizure, rehabilitation, drug use, cognition

Introduction Status epilepticus (SE) is defined as a continuous unremitting seizure lasting for more than 30 minutes or two or more sequential episodes of seizure activity without full recovery of consciousness between seizures. Common causes of SE include low blood levels of anti-convulsants, a cerebrovascular accident, hypoxia/anoxia, metabolic disturbances and medication-induced SE; the frequency of medication-induced seizures is 13% of all seizures. Cefazolin is a well-known antibiotic used to induce SE [1]. The mechanism of cephazolin-induced convulsions is associated with the inhibition of GABAA receptor activity. Thus, cefazolin can

cause massive depolarization of neurons in the central nervous system, resulting in seizures and coma [2]. After SE, transient dysarthria can develop. However, there is no prior report of persistent dysarthria after SE without any structural lesions on anatomical imaging studies such as brain computed tomography (CT) or magnetic resonance imaging (MRI). In addition, in the previously reported case of SE after intrathecal infusion of cefazolin, the patient fully recovered without sequelae [3]. This study reports a case of persistent dysarthria and residual cognitive impairment without any structural brain lesions after cefazolin-induced SE and discusses the possible pathomechanisms.

Correspondence: Sung-Bom Pyun, MD, PhD, Department of Physical Medicine and Rehabilitation, Korea University Medical Center, Anam Hospital, 5-Ga 126-1, Anam-Dong, Sungbuk-gu, Seoul, 136-705, South Korea. Tel: þ82-2-920-6480. Fax: +82-2-929-9951. E-mail: [email protected] ISSN 0269–9052 print/ISSN 1362–301X online ß 2009 Informa Healthcare Ltd. DOI: 10.1080/02699050903196704

Dysarthria after status epilepticus


Case A 66-year-old right-handed woman visited the Department of Physical Medicine and Rehabilitation (PMR) for treatment of low back pain radiating down to the right lower extremity. She was a housewife and had a total of 6 years of education. One year previously she had been diagnosed with lumbar spinal stenosis at the L4/5 level and her symptoms did not improve after several sessions of selective nerve block. The medical history revealed hypertension and two histories suggesting transient ischemic attack (TIA) in the last 2 years; however, the findings of the brain magnetic resonance imaging (MRI) were normal at that time. In addition, she denied any residual neurologic symptoms, a history of seizures, speech problems or cognitive impairment. She underwent epidural adhesiolysis for spinal stenosis on the event day at the outpatient clinic. During the procedure, the dura was punctured incidentally and a mixture of preventive antibiotics, including a total amount of 500 mg of cefazolin and non-ionic contrast material (OmnipaqueÕ ), were infused into the cerebrospinal fluid (CSF). Her vital signs were stable during the procedure, but mental changes and continuous general tonic-clonic seizures suddenly developed 40 minutes after the epidural adhesiolysis was completed. The patient was transferred to the emergency room, but the seizures lasted for more than 1 hour. The patient was diagnosed with SE and admitted to the Department of Neurology and managed in the intensive care unit for seizure control. The seizure activity persisted for 3 days under coma therapy with midazolam and the waking electroencephalography (EEG) findings normalized 5 days after the onset of seizures. After the cessation of SE, the patient was weaned off the ventilator 1 week after the onset of SE. Severe dysarthria, aphonia, dysphagia and impaired cognition were present at that time and the patient also exhibited standing and gait balance difficulties. The brain MRI showed no newly developed lesions. The patient was unable to communicate verbally until 2 weeks after the event. Speech and language testing was performed by a speech-language pathologist. The language test using the Korean version of Western Aphasia Battery (K-WAB) showed correct responses to simple yes/no questions for auditory comprehension. The patient communicated with simple gestures and head nodding during the evaluation. However, communication by writing was not possible. The patient was nearly aphonic and spontaneous speech could not be evaluated. Speech therapy was started to improve the auditory comprehension and communication skills. Oral feeding was not permitted due to severe dysphagia. A videofluorographic study for swallowing (VFSS)

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performed 3 weeks after the onset of symptoms revealed mild penetration of thin and semi-liquid materials and oral feeding was started with dietary modification. Thirty-four days after the initial event, the patient was transferred to the department of PMR for intensive rehabilitation. At the time of transfer, the physical and neurological examination showed an alert mental status and the motor and sensory functions of all four limbs were intact. The patient required minimal assistance during ambulation due to dynamic standing balance difficulty. The dysphagia significantly improved and no penetration signs were observed on the follow-up VFSS, performed at 2 weeks after transfer. The domain-specific cognitive function was evaluated 40 days after the initial event using the Computerized Neurocognition Test (CNTÕ , MaxMedica, Korea), which consisted of diverse standardized neuropsychological tests: digit and visual span tests for attention and working memory, auditory and visual continuous performance tests for vigilance, verbal and visual learning tests for memory and learning, the stroop test for selective attention and inhibition, the trail making test for cognitive flexibility and executive functions, the card sorting test for concept generation and cognitive set shifting, in addition to the Raven’s coloured progressive matrices for nonverbal intelligence [4]. The results showed severe impairment in attention, memory and executive functions. The verbal communication improved at the time of transfer, but severe dysarthria persisted. Cranial nerve examination showed intact facial sensory and a symmetrical face. However, the gag reflex was decreased and the lip and tongue motion was limited. The follow-up K-WAB results at the time of transfer showed normal auditory comprehension. Motor speech evaluation revealed that the maximal phonation time was markedly decreased to 2 seconds. The voice was strained, strangled and harsh. The speaking rate was slow and the articulation of consonants was imprecise. These characteristics suggested spastic dysarthria due to an upper motor neuron lesion. The patient received daily physical therapy for gait and balance training and occupational therapy for oromotor stimulation and cognitive impairment. Speech therapy was performed 1 hour a day, 5 hours a week, for 7 months. The treatment was focused on improving respiration control, speech intelligibility, speech naturalness and training for the control of the rate of speaking. After completing the rehabilitation programme, the gait improved rapidly and she was able to walk independently. Follow-up evaluation of cognitive function by CNT at 4 and 8 months after the initial event showed some improvement in attention and registration during the verbal learning

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Y. Lee et al. Table I. Follow-up results of cognitive function tests.


Sub-tests (maximum score) Digit span test Forward (8) Back word (7) Visual span test Forward (8) Back word (7) Auditory CPT (135) Visual CPT (135) Verbal learning test 1st trial (15) 5th trial (15) delayed recall (15) Visual learning test 1st trial (15) 5th trial (15) delayed recall (15) Stroop test Word of colour word (sec) Colour of colour word (sec) Trail making test Set A (sec) Set B (sec) Card sorting test (6) Raven CPM (calculated IQ)

15 February 2008 (%)

3 (0.5)* 2 (0.5)* 5 3 64 133

(2.3)* (2.3)* (0.5)* (5.0)*

26 June 2008 (%)

3 (0.5)* 3 (2.3)* 6 4 77 132

(43.0) (5.0)* (0.5)* (28.0)

1 (5.0)* 7 (0.5)* 4 (0.5)*

6 (35.0) 7 (0.5)* 5 (0.5)*

12 (92.5) 13 (65.0) 12 (85.0)

12 (92.5) 11 (65.0) 12 (72.0)

60.1 (0.5)* 127.5 (0.5)*

45.7 (0.5)* 162.4 (0.5)*

70 (0.5)* 248 (0.5)* 4 (10.0)