Intraventricular tension pneumocephalus and cervical subarachnoid pneumorrhachis in a bull mastiff dog after craniotomy

Dynamics and diagnosis of severe pneumocephalus of unknown etiology in dog

Modern veterinary medicine and its subdivision – veterinary neurology, are constantly evolving. New diagnostic methods are emerging every day, and the list of new, previously unexplored animal diseases is expanding. Much information about the pathogenesis and etiology of diseases is borrowed from human medicine, which is a big problem, because human physiology is different from animals and, as a consequence, the dynamics of the disease are also different. That is why the continuous improvement of veterinary therapy and diagnosis of diseases is relevant and necessary. One of the rare and severe pathologies is pneumocephalus. It is reported that this is a condition in which there is a gradual accumulation of air in the cranial cavity or ventricles of the brain, creating a life-threatening condition. It is considered that pneumocephalus can occur spontaneously but, in most cases, is diagnosed after trauma or surgery with impaired integrity of the skull bones and meninges. This article describes a case of pneumocephalus of unknown etiology in a young dog who suffered a head injury while playing with the owner. During the neurological examination of the animal conducted immediately after the incident was diagnosed with severe central nervous system lesions (sopor, opisthotonus, tetraparesis); magnetic resonance imaging revealed significant brain damage with pronounced ventricular dilatation and the formation of a cavity filled with air. Re-diagnosis after 14 days showed progression of pneumocephalus with gas accumulation in the brain cavities. The contents of the ventricles have a division into liquid (cerebrospinal fluid), and air, progressive inflammatory processes in the brain's parenchyma were not observed; a fistula or canal connecting the cranial cavity and the external environment was not detected. Symptomatic and supportive therapy, carried out during the entire period of the dog's stay in the veterinary clinic, did not have positive results. The animal was euthanized according to medical indications and the owner's wishes.

Clinical presentation, diagnostic findings and outcome of dogs undergoing surgical resection for intracranial meningioma: 101 dogs

Background

Meningioma is the most common primary brain neoplasm in dogs. Further information is required regarding the expected long-term prognosis of dogs following the surgical resection of an intracranial meningioma together with the influence of adjunctive therapies. Whilst there have been several studies reporting the long-term outcome of intracranial meningioma resection following surgery alone, surgery with the use of an ultrasonic aspirator, surgery combined with radiotherapy and surgery combined with the addition of hydroxyurea, it is currently unclear which type of adjunctive therapy is associated with the most favourable outcomes. The objective of this study is to describe the presentation and outcome of dogs undergoing surgery for the resection of an intracranial meningioma and the effect of clinical factors, adjunctive therapies and meningioma histopathological subtype on the long-term outcome.

Results

A hundred and one dogs that had intracranial surgery for meningioma resection were investigated from four referral centres. 94% of dogs survived to hospital discharge with a median survival time of 386 days. Approximately 50% of dogs survived for less than a year, 25% survived between 1 and 2 years, 15% survived between 2 and 3 years and 10% survived for greater than 3 years following discharge from hospital. One or more adjunctive therapies were used in 75 dogs and the analysis of the data did not reveal a clear benefit of a specific type of adjunctive therapy. Those dogs that had a transfrontal approach had a significantly reduced survival time (MST 184 days) compared to those dogs that had a rostrotentorial approach (MST 646 days; p < 0.05). There was no association between meningioma subtype and survival time.

Conclusions

This study did not identify a clear benefit of a specific type of adjunctive therapy on the survival time. Dogs that had a transfrontal approach had a significantly reduced survival time. Intracranial surgery for meningioma resection offers an excellent prognosis for survival to discharge from hospital with a median long term survival time of 386 days.

MRI diagnosis of spontaneous intraventricular tension-pneumocephalus in a 10-month-old male Saarloos Wolfdog

A 10-month-old male Saarloos Wolfdog was presented with a history of multiple neurologic deficits that had acutely progressed. Neurologic examination findings localized signs to the cerebrum and brainstem. Magnetic resonance imaging revealed markedly enlarged and gas-filled lateral ventricles with a mass effect leading to cerebellar herniation. A right-sided defect of the cribriform plate with a dysplastic ethmoturbinate was identified as the inlet of air and origin of the intraventricular tension pneumocephalus. Surgical findings were consistent with a ruptured, congenital, nasal meningocele.

Diagnosis, treatment and postsurgical complications in a dog with epileptic seizures and a naso-ethmoidal meningoencephalocele

BACKGROUND

Naso-ethmoidal meningoencephalocele is usually a congenital anomaly consisting of a protrusion of cerebral tissue and meninges into the ethmoidal labyrinth. The condition is a rare cause of structural epilepsy in dogs. We report the clinical presentation, surgical intervention, postoperative complications and outcome in a dog with drug resistant epilepsy secondary to a meningoencephalocele.

CASE PRESENTATION

A 3.3-year-old male neutered Tamaskan Dog was referred for assessment of epileptic seizures secondary to a previously diagnosed left-sided naso-ethmoidal meningoencephalocele. The dog was drug resistant to medical management with phenobarbital, potassium bromide and levetiracetam. Surgical intervention was performed by a transfrontal craniotomy with resection of the meningoencephalocele and closure of the dural defect. Twenty-four hours after surgery the dog demonstrated progressive cervical hyperaesthesia caused by tension pneumocephalus and pneumorrhachis. Replacement of the fascial graft resulted in immediate resolution of the dog's neurological signs. Within 5 months after surgery the dog progressively developed sneezing and haemorrhagic nasal discharge, caused by sinonasal aspergillosis. Systemic medical management with oral itraconazole (7 mg/kg orally q12h) was well-tolerated and resulted in resolution of the clinical signs. The itraconazole was tapered with no relapsing upper airway signs. The dog's frequency of epileptic seizures was not affected by surgical resection of the meningoencephalocele. No treatment adjustments of the anti-epileptic medication have been necessary during the follow-up period of 15 months.

CONCLUSIONS

Surgical resection of the meningoencephalocele did not affect the seizure frequency of the dog. Further research on prognostic factors associated with surgical treatment of meningoencephaloceles in dogs is necessary. Careful monitoring for postsurgical complications allows prompt initiation of appropriate treatment.

Transorbital craniectomy for treatment of frontal lobe and olfactory bulb neoplasms in two dogs

CASE DESCRIPTION

An 8-year-old spayed female Shih Tzu crossbreed dog (dog 1) and a 13-year-old neutered male Miniature Fox Terrier (dog 2) were evaluated for removal of neoplasms involving both the frontal lobe and olfactory bulb.

CLINICAL FINDINGS

Physical examination revealed decreased menace response and behavioral changes in both dogs. For dog 1, neuroanatomic localization of the lesion was the left forebrain region; for dog 2, neuroanatomic localization of the lesion was the right forebrain region. Both dogs underwent CT, and dog 1 also underwent MRI. Results of diagnostic imaging were consistent with frontal lobe and olfactory bulb neoplasia in both cases. Dog 1 had lysis of the frontal bone adjacent to the neoplasm.

TREATMENT AND OUTCOME

Both dogs underwent a transorbital craniectomy to permit surgical tumor removal. Dog 1 was discharged from the hospital 48 hours after surgery, at which time its mentation and cranial nerve examination findings were considered normal. Dog 2 developed neurologic deterioration after surgery but was ultimately discharged from the hospital after 72 hours, at which time its mentation appeared normal.

CLINICAL RELEVANCE

The transorbital approach to the cranium provided excellent access to facilitate removal of frontal lobe and olfactory bulb neoplasms in these 2 dogs.

Incidence of and risk factors for major complications or death in dogs undergoing cytoreductive surgery for treatment of suspected primary intracranial masses

OBJECTIVE To determine incidence of and risk factors for major complications occurring in dogs within 30 days after cytoreductive surgery performed by a single pair of surgeons for treatment of suspected primary intracranial masses. DESIGN Retrospective cohort study. ANIMALS 160 client-owned dogs that underwent cytoreductive surgery for treatment of suspected primary intracranial masses between January 2009 and December 2015 at a veterinary teaching hospital. PROCEDURES Medical records were retrospectively reviewed for complications occurring within 30 days after surgery. Data (eg, signalment, clinical signs, previous treatments, preoperative neurologic examination findings, neuroanatomical location, time from onset of clinical signs to surgery, surgical approach, and histopathologic diagnosis) were analyzed for associations with death and with development of major complications other than death. RESULTS 21 (13.1%) dogs died (11 during hospitalization and 10 after discharge) and 30 (18.8%) developed major complications other than death during the first 30 days after surgery. Dogs with abnormal preoperative neurologic examination findings were more likely to develop complications or die. Dogs undergoing a suboccipital approach were more likely to die. The most common postoperative complications other than death were seizures (n = 18 [11.3%]), worsening of neurologic status (6 [3.8%]), and aspiration pneumonia (6 [3.8%]). CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study provided valuable information on predisposing factors, odds of major complications or death, and incidences of major complications or death in dogs during the first 30 days after undergoing cytoreductive surgery for treatment of suspected primary intracranial masses. Careful case selection may help improve outcomes and minimize complications.

Delayed asymptomatic progressive intraventricular pneumocephalus in a dog following craniotomy

Delayed pneumocephalus developed in a 9-year-old dog following transfrontal craniotomy and implantation of an experimental local chemotherapy into a partially resected oligodendroglioma, but the animal appeared to be asymptomatic. MRI evidence of increasing intracranial pressure, including progressive ventricular dilatation and compression of periventricular parenchyma, led to the recommendation for exploratory craniotomy. The barrier between the intracranial cavity and frontal sinus was enhanced, and pneumocephalus resolved on MRI at both 1 and 3 months following the repair.

Epidural Gas Accumulation in Connection with Canine Degenerative Lumbosacral Disease

Three dogs were presented with lumbosacral hyperesthesia. Computerized tomography scans were performed in all the cases, and magnetic resonance imaging was also performed in cases 1 and 3. There was intervertebral disc (IVD) protrusion causing nerve root compression and epidural gas accumulation in all the three cases. The gas-filled cystic structures in cases 1 and 3 were within the spinal canal; in case 2, the gas was within the disc protrusion. The IVD vacuum phenomenon is relatively common in dogs, but the formation of an epidural gas accumulation in cases of a lumbar disc protrusion is rare. The clinical significance of these epidural gas accumulations is unknown. Two of the dogs were treated surgically, improved after surgery, and showed no signs of pain in the follow-up examinations.

Postoperative symptomatic haematoma and pneumorrhachis in a dog with a thoracolumbar intervertebral disc extrusion

CASE REPORT

A 6-year-old male neutered crossbreed dog presented with acute onset paraparesis and was diagnosed with an L1-L2 intervertebral disc extrusion. A right-sided T13-L2 hemilaminectomy was performed. However, the dog deteriorated and became paraplegic with marked thoracolumbar hyperaesthesia 48 h after surgery. A computed tomography scan of the thoracolumbar vertebral column revealed the presence of pneumorrhachis (PR) at the level of T13, possibly embedded in a haematoma, and causing marked spinal cord compression. Revision surgery confirmed the presence of a haematoma, which was removed. The dog gradually improved and was neurologically normal 6 weeks after surgery.

CONCLUSION

Although PR is a rare condition, it may be considered a possible cause for early postoperative neurological deterioration in dogs undergoing decompressive spinal surgery. Surgical revision resulted in a good outcome in the presented case.

Pneumorrhachis in a rottweiler

An 8·5-year-old, female, neutered, Rottweiler was presented for investigation of progressive ataxia of one week duration. Proprioception was absent in the left pelvic limb and reduced on the right, thoracolumbar hyperalgesia was evident and pelvic limb segmental spinal reflexes were normal. Magnetic resonance imaging (MRI) demonstrated a spherical region of signal void compressing the spinal cord between the fifth and sixth thoracic vertebrae and several non-compressive degenerate intervertebral discs. Computed tomography (CT) of the region confirmed the findings and identified the lesion as gas. A dorsolateral hemilaminectomy was performed to decompress the spinal cord and achieved complete resolution of the clinical signs on examination after 3 months. This is the first known reported case of spontaneous pneumorrhachis in a veterinary patient.

Traumatic pneumocephalus in a dog

CASE DESCRIPTION

A 17-month-old dog was evaluated because of progressive tetraparesis. The dog had a history of craniofacial trauma at 2 months of age.

CLINICAL FINDINGS

Results of a neurologic examination were suggestive of a lesion localized to the medulla. Computed tomography revealed extensive pneumocephalus extending throughout the ventricular system and into the cranial cervical subarachnoid space.

TREATMENT AND OUTCOME

Because of the deterioration in the dog's clinical condition, an emergency bilateral transfrontal craniectomy was performed. A large amount of pyogranulomatous material was found intraoperatively. Neurologic and computed tomographic abnormalities were no longer evident during a recheck examination 8 weeks after surgery.

CLINICAL RELEVANCE

Findings suggested that pneumocephalus should be considered in the differential diagnosis for dogs with neurologic signs of an intracranial abnormality, particularly if the dog has a history of craniofacial trauma.