Neuroradiology DOI 10.1007/s00234-015-1509-5
LETTER TO THE EDITOR
A rare cause of reversible ophthalmoplegia: tension pneumocephalus with brainstem compression Samuel A. Lindner & Ian F. Pollack & Hoda Abdel-Hamid & Giulio Zuccoli
Received: 22 February 2015 / Accepted: 2 March 2015 # Springer-Verlag Berlin Heidelberg 2015
Dear Sir, Pneumocephalus is defined as air in the cranial space from pathological communication with extracranial air [1]. Tension pneumocephalus (TP) is a rare condition that occurs after neurosurgical procedures, trauma, or infection by a gas-forming organism [2]. Symptoms depend on the structures involved and may include oculomotor and abducens nerve palsy [3]. We report a patient with cranial nerve (CN) palsies in the setting of TP. An 18-year-old man, with a history of a shunted hydrocephalus since infancy with a fourth ventricular and frontal ventriculoperitoneal (VP) shunt, presented to the Emergency Department with emesis and abdominal pain. A CT of the head showed increased ventricular size. A shunt tap was performed that grew Gram-positive rods consistent with Propionibacterium acnes. The patient subsequently underwent removal of his ventriculoperitoneal shunts in both the right frontal and fourth ventricles and placement of a right frontal external ventricular drain (EVD) and a fourth external ventricular drain.
S. A. Lindner University of Pittsburgh School of Medicine, Pittsburgh, PA, USA I. F. Pollack Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA H. Abdel-Hamid Department of Child Neurology, Childrens Hospital of Pittsburgh at the University of Pittsburgh School of Medicine, Pittsburgh, PA, USA G. Zuccoli (*) Section of Neuroradiology, Children’s Hospital of Pittsburgh at the UPMC, 4401 Penn Avenue, Floor 2, Pittsburgh, PA 15224, USA e-mail: [email protected]
Following surgery, the patient remained with his external ventricular drains in place and approved for a new VP shunt after 7 days of negative cultures and cerebrospinal fluid (CSF). While awaiting placement of a new shunt on postoperative day 6, he had a bout of emesis and broke off the catheters for both of his external ventricular drains close to their exit sites in his head. A repeated CT of the head showed that the EVDs were still in the ventricles, but he had pneumocephalus with gas in the fourth ventricle and proximal aqueduct of Sylvius compressing the dorsal brainstem. Shortly after, he was noted to develop ophthalmoplegia and multiple CN neuropathies. His examination revealed bilateral equal pupils, round and reactive to light. He did have right CN III palsy with complete ptosis and left CN VI palsy with limited lateral abduction. His left eye showed complete ophthalmoplegia consistent with left CN III, IV, and VI palsies. CSF cultures showed growth of Gram-positive cocci. The patient was taken to the operating room again for removal of his external ventricular drains and placement of new external ventricular drains due to concerns of infection. Because of the acute ocular palsies, MRI of the brain was obtained that showed gas entrapment in the aqueduct of Sylvius causing edema in the dorsal brainstem, likely accounting for his cranial nerve deficits with the exception of the left CN VI palsy (Fig. 1a, b). The fourth ventricular peritoneal shunt was noted to compress the pons in the region of the left CN VI nucleus (not shown). He was monitored for several days until placement of a new left frontal VP shunt and fourth ventricular peritoneal shunt. Following the completion of his antibiotic course, the patient was deemed stable for discharge. On follow-up, he was noted to have resolution of his cranial neuropathies correlating with the resolution of pneumocephalus (Fig. 1c, d) and fourth ventricle VP shunt removal. Tension pneumocephalus may represent a major lifethreatening postoperative complication [4]. This case
Neuroradiology Fig. 1 A locule of gas entrapped within the inferior aspect of the aqueduct of Sylvius is identified on mid-sagittal T1-weighted images (a, arrow). Please note the subtle T1 hypointensity anterior to the locule of gas representing vasogenic edema. Midbrain edema (b, arrows) is noted on the midline at the same level of the gas locule. Short-term MRI follow-up demonstrates reabsorption of the gas locule (c) and resolution of the midbrain edema (d)
demonstrates that even a tiny gas locule may create enough pressure to cause CN palsies. The concomitant finding of a possible infection is most likely incidental given the strict anatomical relationship between the entrapped air and the dorsal brainstem as demonstrated by MRI. Although pneumocephalus has been described following cranial surgery and bacterial infection, the development of cranial nerve palsy in the setting of pneumocephalus may be considered exceedingly rare [5]. CN III and VI require considerably high forces to result in functional impairment [6]. The specific symptoms depend on the intracranial distribution of the air. The CN III and VI cell bodies are located in the anterior brainstem near the fourth ventricle. The patient had a fourth ventricular peritoneal shunt with its tip ending in the region of the left CN VI nucleus, likely accounting for the unilateral left CN VI palsy. Interestingly, the patient preserved his pupillary function probably due to sparing of the Edinger-Westphal nucleus which is located more rostrally within the brainstem [7]. As little as 25 mL of air can cause tension pneumocephalus [8]. As there is a small area of potential spaces that the CN nuclei traverse through, even a small amount of trapped air would result in enough compressive force to cause focal CN dysfunction as shown in our patient. Ethical standards and patient consent We declare that all human and animal studies have been approved by the University of Pittsburgh IRB and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. We declare that this patient gave informed consent prior to inclusion in this study.
Conflict of interest We declare that we have no conflict of interest.
References 1. Marupudi NI, Mittal M, Mittal S (2013) Delayed pneumocephalusinduced cranial neuropathy. Case Rep Med 2013:105087. doi:10. 1155/2013/105087 2. Schirmer CM, Heilman CB, Bhardwaj A (2010) Pneumocephalus: case illustrations and review. Neurocrit Care 13:152–158. doi:10. 1007/s12028-010-9363-0 3. Markham JW (1967) The clinical features of pneumocephalus based upon a survey of 284 cases with report of 11 additional cases. Acta Neurochir (Wien) 16:1–78 4. Prakash PS, Jain V, Sandhu K et al (2009) Brain stem tension pneumocephalus leading to respiratory distress after subdural haematoma evacuation. Eur J Anaesthesiol 26:795–797. doi:10. 1097/EJA.0b013e32832b1776 5. Stevens QE, Colen CB, Ham SD et al (2007) Delayed lateral rectus palsy following resection of a pineal cyst in sitting position: direct or indirect compressive phenomenon? J Child Neurol 22:1411–1414. doi:10.1177/0883073807307094 6. Tubbs RS, Wellons JC, Blount JP et al (2007) Forces necessary for the disruption of the cisternal segments of cranial nerves II through XII. Clin Anat N Y N 20:252–255. doi:10.1002/ca.20254 7. Kozicz T, Bittencourt JC, May PJ et al (2011) The Edinger-Westphal nucleus: a historical, structural and functional prospective on a dichotomous terminology. J Comp Neurol 519:1413–1434. doi:10.1002/cne. 22580 8. Aoki N, Sakai T (1993) Computed tomography features immediately after replacement of haematoma with oxygen through percutaneous subdural tapping for the treatment of chronic subdural haematoma in adults. Acta Neurochir (Wien) 120:44–46
LETTER TO THE EDITOR
A rare cause of reversible ophthalmoplegia: tension pneumocephalus with brainstem compression Samuel A. Lindner & Ian F. Pollack & Hoda Abdel-Hamid & Giulio Zuccoli
Received: 22 February 2015 / Accepted: 2 March 2015 # Springer-Verlag Berlin Heidelberg 2015
Dear Sir, Pneumocephalus is defined as air in the cranial space from pathological communication with extracranial air [1]. Tension pneumocephalus (TP) is a rare condition that occurs after neurosurgical procedures, trauma, or infection by a gas-forming organism [2]. Symptoms depend on the structures involved and may include oculomotor and abducens nerve palsy [3]. We report a patient with cranial nerve (CN) palsies in the setting of TP. An 18-year-old man, with a history of a shunted hydrocephalus since infancy with a fourth ventricular and frontal ventriculoperitoneal (VP) shunt, presented to the Emergency Department with emesis and abdominal pain. A CT of the head showed increased ventricular size. A shunt tap was performed that grew Gram-positive rods consistent with Propionibacterium acnes. The patient subsequently underwent removal of his ventriculoperitoneal shunts in both the right frontal and fourth ventricles and placement of a right frontal external ventricular drain (EVD) and a fourth external ventricular drain.
S. A. Lindner University of Pittsburgh School of Medicine, Pittsburgh, PA, USA I. F. Pollack Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA H. Abdel-Hamid Department of Child Neurology, Childrens Hospital of Pittsburgh at the University of Pittsburgh School of Medicine, Pittsburgh, PA, USA G. Zuccoli (*) Section of Neuroradiology, Children’s Hospital of Pittsburgh at the UPMC, 4401 Penn Avenue, Floor 2, Pittsburgh, PA 15224, USA e-mail: [email protected]
Following surgery, the patient remained with his external ventricular drains in place and approved for a new VP shunt after 7 days of negative cultures and cerebrospinal fluid (CSF). While awaiting placement of a new shunt on postoperative day 6, he had a bout of emesis and broke off the catheters for both of his external ventricular drains close to their exit sites in his head. A repeated CT of the head showed that the EVDs were still in the ventricles, but he had pneumocephalus with gas in the fourth ventricle and proximal aqueduct of Sylvius compressing the dorsal brainstem. Shortly after, he was noted to develop ophthalmoplegia and multiple CN neuropathies. His examination revealed bilateral equal pupils, round and reactive to light. He did have right CN III palsy with complete ptosis and left CN VI palsy with limited lateral abduction. His left eye showed complete ophthalmoplegia consistent with left CN III, IV, and VI palsies. CSF cultures showed growth of Gram-positive cocci. The patient was taken to the operating room again for removal of his external ventricular drains and placement of new external ventricular drains due to concerns of infection. Because of the acute ocular palsies, MRI of the brain was obtained that showed gas entrapment in the aqueduct of Sylvius causing edema in the dorsal brainstem, likely accounting for his cranial nerve deficits with the exception of the left CN VI palsy (Fig. 1a, b). The fourth ventricular peritoneal shunt was noted to compress the pons in the region of the left CN VI nucleus (not shown). He was monitored for several days until placement of a new left frontal VP shunt and fourth ventricular peritoneal shunt. Following the completion of his antibiotic course, the patient was deemed stable for discharge. On follow-up, he was noted to have resolution of his cranial neuropathies correlating with the resolution of pneumocephalus (Fig. 1c, d) and fourth ventricle VP shunt removal. Tension pneumocephalus may represent a major lifethreatening postoperative complication [4]. This case
Neuroradiology Fig. 1 A locule of gas entrapped within the inferior aspect of the aqueduct of Sylvius is identified on mid-sagittal T1-weighted images (a, arrow). Please note the subtle T1 hypointensity anterior to the locule of gas representing vasogenic edema. Midbrain edema (b, arrows) is noted on the midline at the same level of the gas locule. Short-term MRI follow-up demonstrates reabsorption of the gas locule (c) and resolution of the midbrain edema (d)
demonstrates that even a tiny gas locule may create enough pressure to cause CN palsies. The concomitant finding of a possible infection is most likely incidental given the strict anatomical relationship between the entrapped air and the dorsal brainstem as demonstrated by MRI. Although pneumocephalus has been described following cranial surgery and bacterial infection, the development of cranial nerve palsy in the setting of pneumocephalus may be considered exceedingly rare [5]. CN III and VI require considerably high forces to result in functional impairment [6]. The specific symptoms depend on the intracranial distribution of the air. The CN III and VI cell bodies are located in the anterior brainstem near the fourth ventricle. The patient had a fourth ventricular peritoneal shunt with its tip ending in the region of the left CN VI nucleus, likely accounting for the unilateral left CN VI palsy. Interestingly, the patient preserved his pupillary function probably due to sparing of the Edinger-Westphal nucleus which is located more rostrally within the brainstem [7]. As little as 25 mL of air can cause tension pneumocephalus [8]. As there is a small area of potential spaces that the CN nuclei traverse through, even a small amount of trapped air would result in enough compressive force to cause focal CN dysfunction as shown in our patient. Ethical standards and patient consent We declare that all human and animal studies have been approved by the University of Pittsburgh IRB and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. We declare that this patient gave informed consent prior to inclusion in this study.
Conflict of interest We declare that we have no conflict of interest.
References 1. Marupudi NI, Mittal M, Mittal S (2013) Delayed pneumocephalusinduced cranial neuropathy. Case Rep Med 2013:105087. doi:10. 1155/2013/105087 2. Schirmer CM, Heilman CB, Bhardwaj A (2010) Pneumocephalus: case illustrations and review. Neurocrit Care 13:152–158. doi:10. 1007/s12028-010-9363-0 3. Markham JW (1967) The clinical features of pneumocephalus based upon a survey of 284 cases with report of 11 additional cases. Acta Neurochir (Wien) 16:1–78 4. Prakash PS, Jain V, Sandhu K et al (2009) Brain stem tension pneumocephalus leading to respiratory distress after subdural haematoma evacuation. Eur J Anaesthesiol 26:795–797. doi:10. 1097/EJA.0b013e32832b1776 5. Stevens QE, Colen CB, Ham SD et al (2007) Delayed lateral rectus palsy following resection of a pineal cyst in sitting position: direct or indirect compressive phenomenon? J Child Neurol 22:1411–1414. doi:10.1177/0883073807307094 6. Tubbs RS, Wellons JC, Blount JP et al (2007) Forces necessary for the disruption of the cisternal segments of cranial nerves II through XII. Clin Anat N Y N 20:252–255. doi:10.1002/ca.20254 7. Kozicz T, Bittencourt JC, May PJ et al (2011) The Edinger-Westphal nucleus: a historical, structural and functional prospective on a dichotomous terminology. J Comp Neurol 519:1413–1434. doi:10.1002/cne. 22580 8. Aoki N, Sakai T (1993) Computed tomography features immediately after replacement of haematoma with oxygen through percutaneous subdural tapping for the treatment of chronic subdural haematoma in adults. Acta Neurochir (Wien) 120:44–46
