A 15 year old girl presented to the ER with coma following several tonic–clonic convulsions.\nThe patient was previously healthy with no personal or familial medical history. During her visit to a dentist for endodontic treatment, the dentist injected 1.5 ml of 2 % lidocaine (the total dose was 30 mg) and epinephrine 1:100,000 for local anesthesia. The solution was injected on the left side by an expert hand without prior aspiration.\nThe injection lasted about 2 min. By the end of the injection, the girl collapsed and several intermittent tonic–clonic convulsions ensued. These lasted about 30 min and were followed by deep coma.\nGlasgow coma scale (GCS) was three, brainstem reflexes were intact, and no fever was noticed. Vital signs were within normal limits.\nHer left cheek and gingiva were edematous and a giant gingival hematoma was noticed.\nOptic disc examination showed no edema.\nElectrocardiogram (ECG) was normal except for sinus tachycardia (120 beat per minute).\nElectroencephalography (EEG) showed diffuse slow activity, predominately theta rhythms, with no signs of continuous status epilepticus.\nBrain computed tomography (CT) revealed reduced white–gray matter differentiation with effacement of cerebral sulci which was compatible with cerebral edema.\nBrain magnetic resonance imaging with venogram (Fig. ) and angiogram (Fig. ) MRI + MRV + MRA showed cerebral edema, bilateral and almost symmetric hyperintense T2 lesions with restricted diffusion in both frontal and occipital lobes (Fig. ), and no underlying cerebral venous thrombosis CVT.\nLumbar puncture was performed and revealed the following results: 10 lymphocytes, elevated protein (50 mg/dl), no RBCs, and negative gram stain. Whereas blood glucose was 50 mg/dl, CSF glucose was 70.\nOrdinary labs including Calcium, Albumin, MG, Na, K, creatinine, urea, LFTs, CBC, Plt, PT, PTT, and INR were all normal and troponin was negative.\nThe patient was admitted to the ICU and intubated.\nPhenytoin at dose 15 mg/kg was loaded with close cardiac monitoring, and a maintenance dose of 100 mg twice daily was initiated in the second day.\nA bolus (1 g/kg) of Mannitol was given intravenously, followed by a maintenance dose of 0.5 g/kg/8 h. GCS, consequently, improved to nine in 2 days.\nThe patient recovered completely and was discharged after a week of admission.
An 8-year-old healthy male patient (30 kg weight and 130 cm height) with no history of epilepsy visited the dentist for tooth extraction. The patient had no known drug allergies. During his visit for extraction of deciduous second molar, the dentist injected 1.8 ml of 2% lignocaine (36 mg) with adrenaline (1:200,000) after prior aspiration at upper left maxillary vestibule with respect to deciduous second molar followed by 0.5 ml at left greater palantine nerve block. The total 46 mg lignocaine lasting over 2 min was administered. Immediately following the nerve block, the child presented with tonic-clonic convulsions. Patient was placed in supine position with elevated legs, and care was taken so as to protect from injuries. Injection diazepam was given. The vital signs and all laboratory investigations were normal. Neurological examination was unremarkable. MRI scan of the head and electroencephalogram were normal. There was no recurrence of seizures and the child was discharged after 1 day. Using Naranjo probability scale the relationship between the drug and the event was categorized as probable.