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.
Patient 2 was a previously healthy, 52-year-old male with a spontaneous complete rupture of the left supraspinatus tendon. The patient received an arthroscopic rotator cuff repair, and a single-injection ISB combined with TIVA was selected as the anesthetic strategy. Preprocedural BP was 130/60 mm Hg; HR 66 bpm; SpO2 values 99–100%. After ultrasound- and PNS-guided placement of a left ISB, the brachial nerve block was performed by injecting 1% lidocaine (10 mL) followed by 0.375% ropivacaine (10 mL). There was a negative aspiration test for blood and cerebrospinal fluid prior to injection. Physical examination revealed an effective interscalene block. Adverse cardiac or neurologic symptoms were not recorded. After induction of anesthesia, and intubation, TIVA was maintained with propofol and sufentanil. BP was measured every 5 min with a noninvasive cuff. The patient underwent an uneventful operative rotator cuff repair under the ISB and intravenous anesthesia. Intraoperatively, recorded SBP levels of 100–120 mmHg were interrupted by SBP levels of ≥90 and <100 mmHg for a maximum of 35 min due to the application of controlled hypotension. Administration of antihypertensive and/or vasoconstrictor drugs was not recorded. SpO2 (98–100%) and ETCO2 values (34–37%) were normal throughout the case. The duration of surgery was 56 min. After termination of TIVA, and extubation in the OR, the patient presented with impaired consciousness and aphasia, a left-sided gaze preference, dysphagia, mild-to-moderate right-sided central facial palsy, right-sided hemiplegia, and right-sided positive pyramidal tract signs. Brain imaging four hours post-surgery did not detect any cerebral lesions.