caused generalized cortical inhibition and, subsequently the On the other hand, abnormal eye movement, which looks the same as SPPG in coma, has been described in conscious patients with PSP or spinocerebellar degeneration (SCD) in Japanese literature since 1975. In addition to TAS, SWJs corresponding to level 3 in oculomotor dysfunction of the MDS criteria were observed in four out of the five patients with PSP as well as the present patient. Then the smooth PPG shifted permanently to saccadic PPG following clinical improvement ( bottom). Senelick RC. " B: In patient 3, at the beginning of the clinical course, the eyes moved smoothly from one extreme lateral position to the other ( top). With cold caloric stimulation, after a latent period of - 10 s, the eyes deviated to the irrigated side with nystagmus with the slow phase toward the irrigated side for ~ 1 min. Many toxins and drugs administered may also have effects on the size of the pupils, and pharmacologic mydriasis can inadvertently occur in patients treated with aerosols after extubation. This alternating gaze has been described as appearing to be smooth. Yang SL, Han X, Guo CN, Zhu XY, Dong Q, Wang Y. J Neurol. Clinical manifestation and features of so-called TAS (SPPG) in PSP. (B) T1-weighted MRIs, 20 days after initial event, show high signal intensities in bilateral basal ganglia and cortices, and diffuse brain atrophy, which are consistent with hypoxic brain damage. The main cause of PPG is an acute and large ischemic stroke. [Slow, periodic alternating ping-pong gaze and Cheyne-Stokes respiration]. Arch Ophthalmol 1965; 73: 324- 30. In the daylight under a target-off state and in the dark, a single or several SPPG with small amplitude occurred alternately with SWJs. Your last, or family, name, e.g. Neurology. We suggest this eye movement be referred to as SPPG instead of TAS. Unauthorized use of these marks is strictly prohibited. These findings suggest that saccadic PPG is a clinical variant of PPG in patients in a lighter state of consciousness, possibly related to less extensive brain damage. Brain. In addition, in PSP, steady fixation is disrupted by macro SWJs. Information on how to subscribe to Neurology and Neurology: Clinical Practice can be found here. Larmande P, Belin C, Limodin J, Larmande J, Dongmo L. Grandes oscillations pendulaires lentes des globes oculaires et dyspnee de Cheyne- Stokes. Supported by She presented predominant postural instability and saccadic ping-pong gaze (SPPG). However, our electrooculographic study of four consecutive unconscious patients with PPG showed smooth waveforms in one patient but saccadic cog-wheeling in three patients. Before Bedford J. A: The alternating gaze of patient 1 had a cogwheeling quality associated with saccadic components ( saccadic ping- pong gaze [ PPG]). Neurology 26:532-535, 1976. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. What is the likely location of a lesion with ocular bobbing? Intermittently, these movements were followed by slow to-and-fro horizontal eye motion (ping-pong gaze) immediately or with a latency of several seconds (figure, A, arrow; video E-1). government site. Several investigators ( 2, 3,8,11) have reported similar eye movements characterized by short- cycle, spontaneous, alternating conjugate deviation in comatose patients. Ubabe S, Hamamura R, Fujino A, Nakatani S. Progressive supranuclear palsy with transitory alternating saccade; A report of three cases. Her gait was wide-based and short-stepped and characterized by reduced rotation of the trunk. For 2 months before admission, he had convulsions several times a day. Terms of Use| I. Senelick argued that a small hemorrhage found in the midline deep vermis was thought to have disrupted the neural integrator that holds the position of gaze, resulting in PPG (16). Access for 1 day (from the computer you are currently using) is US$ 39.00. 28. Leigh RJ, Hanley DF, Munschauer FE, Lasker AG. Whereas the patient with smooth PPG died immediately, the patients with saccadic PPG survived in a persistent vegetative state. 8. Alternatively, SPPG appeared continuously and got larger (to 50 deg) than in the daylight. Case report: Saccadic ping-pong gaze in progressive supranuclear palsy "Ping-pong" gaze. Periodic alternating gaze deviation - PubMed Department of Neurology, Hospital Universitari de Crevits L, Decruyenaere J. ' PPG is encountered in cases of severe bilateral hemispheric or posterior fossa brain damage with intact brain stem and more rarely during drug toxicity. Your last, or family, name, e.g. System of ophthalmology. A clinicopathologic study of a patient with periodic alternating gaze deviation is presented. This saccadic alternating gaze continued for 5 days. In the comatose patient, cold caloric stimulation indicates a normal brainstem or bilateral hemispheric dysfunction when there is an ipsilateral tonic slow phase. Irrigate 30 to 60 mL of ice water into the external auditory canal using a large syringe and tubing from a butterfly catheter (without the needle); place a basin under the ear to collect the water.4. 3. Vitreous hemorrhage (uni- or bilateral) suggests Terson syndrome (related to acutely raised intracranial pressure, most commonly with subarachnoid hemorrhage). "Ping Pong" gaze, Periodic alternating gaze deviation. Do metabolic causes of coma usually result in large or small pupils? 2014;71(11):1450. doi:10.1001/jamaneurol.2014.1072. The term was coined by Selenick in 1976 after observing the phenomenon in a patient with a cerebellar haemorrhage. Irrigate 30 to 60 mL of ice water into the external auditory canal using a large syringe and tubing from a butterfly catheter (without the needle); place a basin under the ear to collect the water. LH = horizontal position of the left eye; LV = vertical position of the left eye; RH = horizontal position of the right eye; RV = vertical position of the right eye. Many toxins and drugs administered may also have effects on the size of the pupils, and pharmacologic mydriasis can inadvertently occur in patients treated with aerosols after extubation. sharing sensitive information, make sure youre on a federal Because the pathways governing ocular motility traverse the entire brainstem, brainstem lesions will most often result in abnormal eye movements, and the lesion can be localized to the midbrain, pons, or medulla; conversely, if the eye movements are normal, the brainstem is likely to be normal, and bilateral hemispheric or thalamic disease should be suspected. However, SPPG in the present patient occurred in quite different conditions and had several different features from PPG/SPPG in coma. Fisher CM. J Neuroophthalmol. J Neurol Neurosurg Psychiat. Practice healthy basics. Look at Ping-Pong Gaze: An Observational Study and Literature Ping-pong gaze is a more rapid alternation of gaze deviation in comatose patients, occurring every few . Duke- Elder SS. Patient 4 This 68- year- old man was referred to our hospital because of rapidly progressing disturbed consciousness. She was diagnosed as suggestive of PSP with predominant postural instability (5) by a combination of level 3 in oculomotor dysfunction (SWJs) and level 1 in postural instability (unprovoked falls) according to the Movement Disorder Society criteria 2017 (the MDS criteria) for PSP (6). These questions are archived at https://neuro-ophthalmology.stanford.eduFollow https://twitter.com/NeuroOphthQandA to be notified of new neuro-ophthalmology questions of the week.Please send feedback, questions, and corrections to tcooper@stanford.edu. Acute ischemic stroke is the most common cause of PPG. Biousse V and Newman NJ. MeSH Received: 17 November 2022; Accepted: 06 February 2023; Published: 01 March 2023. Smooth periodic alternating gaze continued during head rotation. Leigh RJ, Zee DS (eds.). Address correspondence and reprint requests to Dr. Ken Johkura, Department of Neurology, Urafune Hospital, Yokohama, City University School of Medicine, 3- 46 Urafune- cho, Minami- ku, Yokohama 232, Japan. An 83-year-old woman with a history of multiple episodes of The amplitudes of SWJs were 45 deg under target-on, 56 deg under target-off, and 68 deg in the dark. Conjugate ocular deviation; conjugate lateral eye deviation indicates the following: Brain computed tomography ( CT) showed bilateral cerebral hemisphere contusions with severe swelling. No comments have been published for this article. 2. 5th, ed. In each graph, the upper direction indicates rightward eye movement, and the lower direction indicates leftward. No comments have been published for this article. What is ocular dipping? The ocular dipping and ping-pong gaze resolved over the following several weeks. Submissions must be < 200 words with < 5 references. Finally, over next few hours the patient died because of aspiration the electroencephalogram activity. The am- Manuscript received August 18, 1997. Electroencephalogram (EEG) was requested. (1976) 26:5325. You must ensure that your Disclosures have been updated within the previous six months. Epub 2018 Sep 25. Ocular motility review for 1997-1998: part II. Insight into Ping-Pong Gaze in the Neurosciences Intensive Care Unit. 1212 Article Info & Disclosures Abstract A clinicopathologic study of a patient with periodic alternating gaze deviation is presented. (A) Square wave jerks (SWJs) occurred in the following three conditions: first, in the daylight under the target-on state; second, under the target-off (arrow) state; and finally, light-off (arrow) in the dark. . 27. and continuous conjugate eye deviation alternating every 2 to Metabolic or toxic causes were excluded by blood tests. Because the pathways governing ocular motility traverse the entire brainstem, brainstem lesions will most often result in abnormal eye movements, and the lesion can be localized to the midbrain, pons, or medulla; conversely, if the eye movements are normal, the brainstem is likely to be normal, and bilateral hemispheric or thalamic disease should be suspected.The Glasgow Coma Scale is a neurological score used to record the level of consciousness after a head injury. 2023 American Medical Association. Bilateral disc edema suggests raised intracranial pressure and should raise the possibility of an intracranial mass or hemorrhage, hydrocephalus, cerebral venous thrombosis, or meningitis. Submissions should not have more than 5 authors. 8600 Rockville Pike 4. We describe a PPG case with a synchronous eye movement with Ping Pong Gaze (PPG) is a slow and rhythmical horizontal abnormal All rights reserved. We discuss the differences between PPG/SPPG in coma and SPPG in PSP and the possible pathophysiological mechanism of SPPG in relation to cerebellar oculomotor dysfunctions. Electro-oculographic study of 11 cases]. Bilateral caloric stimulation with cold water produces a downward slow phase. Masucci E, Fabara JA, Saini N, Kurtzke JF. 2011;102:333-78. doi: 10.1016/B978-0-444-52903-9.00019-4. A case of ping-pong gaze of unknown cause. 29. a suppression of the horizontal abnormal alternating ocular -, J Stroke Cerebrovasc Dis. Do metabolic causes of coma usually result in large or small pupils? What the likely location of a lesion with dipping? normal caloric response in an awake patient is when the eyes move slowly toward the irrigated ear, followed by a fast corrective phase to reset the eyes. J Vestib Res. left hemisphere was the representation of the initial insult that Funduscopic examination of the comatose patient is usually performed undilated because pupil monitoring may be important in coma. They described it as horizontal alternating ocular deviation at a period of 3 s on which saccades superimpose and named this phenomenon transitory alternating saccades (TAS). Since then, TAS has been reported in rare cases with PSP (1315) in Japanese (not in English) literature. (2018) 77:7787 (in Japanese with English abstract). and apply to letter. Senelick RC. A Closer Disclaimer. Patient 3 This 67- year- old man suddenly lost consciousness, presumably due to ventricular fibrillation. Additional material related to this article can be found on the Neurology Web site. MeSH PPG either in one hemifield or with a preference has also been plitudes of the eye movements were calibrated using Hir-schberg's corneal reflection test ( 5,10). The patient remained in a persistent vegetative state. One day before admission, he complained of nausea and general fatigue, gradually followed by a decrease in alertness. Online ISSN:1526-632X, The most widely read and highly cited peer-reviewed neurology journal. Neurology 1976; 26: 532-535. years. Larmande P, Henin D, Jam M, et al. Neurosurgery 1987; 20: 481- 2. doi: 10.1093/brain/awm323. A case of surgically-associated anti GQ1b antibody syndrome accompanied With cold caloric stimulation, the eyes deviated tonically to the irrigated side for - 90 s, and then the periodic alternating gaze resumed with increasing amplitude until the original oscillation was restored. 29. C. Disorders of Eye Movements - Neuro-ophthalmology National Library of Medicine Two years earlier, the patient had undergone incomplete surgical removal of a prostatic cancer and was treated by irradiation. Roving eye movements: slow ocular conjugate deviations in random directions (2017) 32:85364. Other causes less commonly described are hypoxic-ischemic Acute ischemic stroke is the most common cause of PPG. 2. Oculocephalic responses were present in both the horizontal and vertical directions. Exercise, a balanced diet, proper hydration, sleep, and managing stress can all help you keep control of heart and mental health conditions, thereby lessening the chance . To our knowledge, we describe the first case of PPG with Keywords: One and a half years after the first examination, along with her progression of postural instability, there appeared mild decrease in range and velocity of vertical gaze (10) (hypometric and stepwise saccades with peak velocity <200 deg/s and with saccade amplitude 20 deg). Pupils (Fig. 13. Lesion in contralateral pons (gaze palsy) (the patient looks away from the lesion) James L. Bernat et al.Neurology, November 01, 2010, Carol Di Perri, Stefano Bastianello, Andreas J. Bartsch et al.Neurology, September 18, 2013, T. C. Frohman, S. Galetta, R. Fox et al.Neurology, May 20, 2008, C. Schnakers, F. Perrin, M. Schabus et al.Neurology, November 10, 2008, DOI: https://doi.org/10.1212/01.wnl.0000242578.31646.1a, Current controversies in states of chronic unconsciousness, Limbic hyperconnectivity in the vegetative state, Pearls & Oy-sters: The medial longitudinal fasciculus in ocular motor physiology, Voluntary brain processing in disorders of consciousness, Neurology: Neuroimmunology & Neuroinflammation. frontal hemispheric (Figure 1). Three previous cases of periodic alternating gaze deviation are reviewed and illustrate the role of the cerebellum in the control of eye movements. It was firstly described by Selenick in 1976 in a patient with cerebellar haemorrhage and it is caused by the lack of cortical inhibition to the Little is known about ping-pong gaze (PPG) outside of individual case reports. doi: 10.1002/ana.410150511, 20. Please go to our Submission Site to add or update your Disclosure information. patient was diagnosed of non-convulsive status epilepticus. (B) In the dark, macro SWJs soon disappeared. 26. Metabolic or toxic causes were excluded by blood tests. One is PPG without saccadic intrusions and the other is saccadic PPG (SPPG). and transmitted securely. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). 11. 7. Nunomura H, Kasahara T, Hatano T, Shimada H, Takado Y, Endo H, Inoshita A, Inomata A, Murofushi T, Misawa S, Machida Y, Imai H. Front Neurol. Spontaneous elevation of a ping-pong fracture: case report and review of the literature. (2014) 232:191210. Clinical diagnosis of progressive supranuclear palsy: the Movement Disorder Society criteria. 1.16 Neuro-ophthalmic Examination of the Comatose By definition, comatose patients have their eyes closed. Leigh RJ, Zee DS. Antiepileptic therapy was started without improvement. His eyes did not oscillate at that time. He had Parkinson's disease treated with levodopa and dopamine agonists for 12 43 44 K. JOHKURA ETAL. Results: Oculocephalic responses were present both in the horizontal and vertical directions. The eyes should deviate in the direction opposite the head turn. At 6 hours from symptom onset, CT scan showed a hypodense lesion in the midbrain tectum, at the collicular level, suggestive of ischaemic stroke (Figure 1D). encephalopathy, post-seizure state - it disappears when the patient become awake -, monoamine oxidase and tricyclic toxicity, The patient is assessed against the criteria of the scale (Table 1.5), and the resulting points give a patient score between 3 (deep unconsciousness) and 15 (normal state). and is reported in patients with posterior fossa lesions ( 13- 15). We would like to express our gratitude to our patient and her husband for their cooperation in the preparation of this report. Disclaimer. She showed no signs of nuchal dystonia, limb tremor, rigidity, spasticity, or limb ataxia. Indicate intact ocular motility function in the brainstem Quattrone A, Nicoletti G, Messina D, Fera F, Condino F, Pugliese P, et al. Dysconjugate ocular deviation: Horizontal, vertical, or oblique misalignment Often indicates a cranial nerve palsy or skew deviation. Leigh RJ, Zee DS, eds. PPG/SPPG in coma usually occurs more steadily and continuously than SPPG in PSP. Submissions should not have more than 5 authors. HHS Vulnerability Disclosure, Help 2016; doi: 10.1523/JNEUROSCI.2600-10.2011, 9. Effect of aging on magnetic resonance measures differentiating progressive supranuclear palsy from Parkinson's disease. Before Neuro-ophthalmic examination is helpful, particularly regarding evaluation of the brainstem. With warm water, the eyes move slowly away from the irrigated ear (fast phase is toward the irrigated ear). She had unprovoked falls recurrently within a year from the onset of gait disturbance. Non-AAN Member subscribers (800) 638-3030 or (301) 223-2300 option 3, select 1 (international) Harvard Medical Faculty Physicians (HMFP), United States, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, China. During the EEG recording, diazepam was administrated intravenously, which caused a change Inspect the tympanic membrane (otoscopy) to exclude rupture or cerumen impaction.3. Pupillary and corneal reflexes were normal. Request PDF | On Jul 1, 2019, Takateru Ihara and others published Ping-Pong Gaze in a Postictal State | Find, read and cite all the research you need on ResearchGate The information below is from Neuro-ophthalmology Illustrated-2nd Edition. 2B, top; Table 1). No-go neurons in the cerebellar oculomotor vermis and caudal fastigial nuclei: planning tracking eye movements. PPG/SPPG is usually seen in unconscious patients with bilateral disconnection of the cerebrum from the midbrain, while the lower brainstem and cerebellum remain largely intact (17, 18). The term PPG was first used in 1979. Ping-pong gaze (PPG), or short-cycle periodic alternating gaze, consists of horizontal conjugate ocular deviations alternating every few seconds. AAN Members (800) 879-1960 or (612) 928-6000 (International) Questions: Lancet Neurol. Caloric stimulation involves the following steps: 1. This SPPG was usually observed in the dark and with eye closure by using EOG. Classification of vestibular signs and examination techniques: Nystagmus and nystagmus-like movements. In each figure, the upper graph shows semi-eye position (time constant 3 s) and the lower graph shows eye speed (time constant 0.03 s). However, our electrooculographic study of four consecutive unconscious patients with PPG showed smooth waveforms in one patient but . According to the reports with EOG in Japan, five patients with PSP showed TAS only in the dark and with eye closure at a period of 26 s and amplitude of 1040 deg with alternating 410 small saccades (Table 1). doi: 10.1007/s00221-013-3731-x, Keywords: progressive supranuclear palsy, postural instability, macro square wave jerks, ping-pong gaze, saccadic ping-pong gaze, transitory alternating saccades, the movement disorder society criteria, case report, Citation: Nunomura H, Kasahara T, Hatano T, Shimada H, Takado Y, Endo H, Inoshita A, Inomata A, Murofushi T, Misawa S, Machida Y and Imai H (2023) Case report: Saccadic ping-pong gaze in progressive supranuclear palsy with predominant postural instability. However, a midrange pupil not responsive to light indicated a lesion involving the brainstem. and transmitted securely. A 16-year-old girl with fever of unknown origin was found comatose in the morning. His pupils were round and reactive. 10. Ping-pong gaze is generally known to be a sign of a poor neurologic prognosis, and reports of ping-pong gaze related to convulsions are few due to the short duration and . "PingPong" gaze | Semantic Scholar Shape 1994; 42: 212-213. However, she remained in vegetative state without recovery for the past 6 months since the initial event. Eventually the patient was diagnosed as having probable PSP by a combination of level 1 in oculomotor dysfunction (vertical supranuclear gaze palsy) and level 1 in postural instability according to the MDS criteria. Accessibility described in patients with unilateral or asymmetric bilateral 1. eCollection 2023. Leigh RJ, Zee DS (eds.). Ping-pong gaze. Neurology 1976; 26: 532- 5. Both eyes moved conjugately in a saccadic fashion from one lateral position to the other, each cycle lasting - 3 s ( Table 1). Ocular motor syndromes caused by the disease of the cerebellum. Individual access to articles is available through the Add to Cart option on the article page. Masucci EF, Fabara JA, Saini M, et al. Ping-Pong Gaze in a Postictal State - The Journal of Pediatrics An 84-year-old man with an acute and progressive disorder of consciousness presented with ping-pong gaze, A-C) and Cheyne-Stokes breathing, suggestive of metabolic or toxic cause. Association of British Neurologists. Periodic alternating gaze (ping-pong gaze), with conjugate roving of the eyes from one extreme of horizontal gaze to . (1984) 15:46573. An official website of the United States government. This eye movement is thought to represent periodic alternating nystagmus ( PAN) without the rapid phases ( 5,13- 15) 3 sec. You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid A storm system that moved across the southern part of the Denver metro area on Thursday brought heavy rain and destructive hail, and a tornado touched down . Ping-pong gaze (PPG), or short-cycle periodic alternating gaze, consists of horizontal conjugate ocular deviations alternating every few seconds. This assumed cause of SPPG in PSP is somewhat similar to that of PPG/SPPG in coma in the light of bilateral disconnection of the cerebrum from the midbrain with visual deprivation. Philadelphia: FA Davis, 1991: 460- 5. We detail SPPG in PSP and discuss the clinical and pathophysiological implications. Web page addresses and e-mail addresses turn into links automatically. (Exception: original author replies can include all original authors of the article). 2015 Mar;24(3):e67-8 However, it has been called transient alternating saccades (TAS). Nowadays, we believe it is more appropriate to call this abnormal eye movement SPPG instead of TAS. SPPG in the present patient with PSP appeared alternately with frequent macro SWJs in the dark, and with eye closure, giant SPPG appeared continuously and SWJs disappeared. YT and HE: execution and writing the figure. Copyright J. Willard Marriott Library. Etiology and initial outcome are likely important prognostic factors of PPG. Given the suspicious of meningoencephalitis, the lumbar Clinical methods of neuro- ophthalmologic examination. FOIA What is ocular dipping? Acute ischemic stroke is the most common cause of PPG. In addition, she showed no signs of peripheral sensory or motor neuropathy. Would you like email updates of new search results? These waveforms had the following features: ( a) the amplitude of the eye deviations were smaller than that of smooth PPG; ( b) the horizontal eye deviations consisted of rapid phases that were directed toward the eye deviation and centripetally directed small slow phases; and ( c) the velocities of rapid phases ranged from 60 to 100 deg/ sec. Periodic alternating gaze (ping-pong gaze), with conjugate roving of the eyes from one extreme of horizontal gaze to the other, holding the extreme position for 2 to 3 seconds. Senelick RC. In the dark, macro SWJs (510 deg) often occurred in a series (Figures 1A, C, D). Spontaneous eye movements, oculocephalic responses elicited by passive head rotation, and cold caloric responses were recorded. Your email address, e.g. Reynard M, Wertenbaker C, Behrens M, et al. " We think the term transitory alternating saccades does not express appropriately the features of this abnormal eye movement because the meaning of transitory is vague in this context. In comatose patients it is a manifestation of hepatic encephalopathy. Do not be redundant. The studies involving human participants were reviewed and approved by the Medical Research Ethics Committee at Tokyo Rinkai Hospital. The Glasgow Coma Scale is a neurological score used to record the level of consciousness after a head injury. doi: 10.1212/WNL.26.6.532, 17. Bilateral caloric stimulation with warm water produces an upward slow phase. (Video) Patient shows periodic eye movements with an initial downward deviation followed by rapid upward correction (ocular dipping), and slow to-and-fro horizontal eye motion (ocular roving, ping-pong gaze). C: In patient 4, the eyes moved smoothly from one extreme lateral position to the other ( smooth PPG). Although acute ischemic stroke is the most common cause of ping-pong gaze in adults, metabolic encephalopathy and intoxication have been reported as other potential causes. Periodic alternating gaze: Electro-oculographic and anatomical observation of a new case. 13. Ishikawa H, Ishikawa S, Mukuno K. Short- cycle periodic alternating ( ping- pong) gaze. synchronous EEG activity. Epub 2023 Feb 28. Eggers SDZ, Bisdorff A, von Brevern M, Zee DS, Kim JS, Perez-Fernandez N, Welgampola MS, Della Santina CC, Newman-Toker DE. At 6 hours from symptom onset, a computed tomographic scan showed a hypodense lesion in the midbrain tectum at the collicular level, suggestive of ischemic stroke (Figure, D). An 83-year-old woman presented to emergency department with 2000 Sep;20(3):192-206. doi: 10.1097/00041327-200020030-00009. because of low level of consciousness accompanied by right eye ocular movements. The cold water creates convection currents in the endolymph of the horizontal semicircular canals and inhibits the ipsilateral vestibular system. FIG. In addition, the degree of severity of SPPG changed according to different conditions. . puncture was performed and the cerebrospinal fluid study (CSF) In 1967, Fisher ( 2) first gave a brief description of PPG in a comatose patient. Polymorphonuclear leukocytes were observed in CSF without evidence of microorganisms.