The Surgery of the Skull and Brain

by Louis Bathe Rawling

SYMPTOMS POINTING TO FRACTURE OF THE POSTERIOR FOSSA

External hæmorrhages.

In fractures of the posterior fossa, blood effused into the deeper tissues of the scalp has considerable difficulty in coming to the surface and thus making itself evident. Furthermore, the resistance offered by the nuchal muscles tends to confine the blood to the subtentorial region, thus adding to the already grave prognosis of fractures in this region. On careful palpation, however, it will be noted that the nuchal tissues present a doughy or boggy condition, whilst ecchymosis becomes evident after twenty-four to thirty-six hours. A peculiar ecchymotic patch is occasionally observed, appearing in front of the mastoid process and travelling upwards in a curved direction, concavity forwards, following the outline of the ear. It is said to result from the tracking of blood along the course of the posterior auricular artery. Whether this is the case or not, the hæmorrhage usually implies a separation along the line of the masto-occipital suture.

Escape of cerebro-spinal fluid.		-	Neither of these symptoms are present.
Escape of brain-matter.

Involvement of nerves.

When dealing with fractures of the middle fossa, allusion was made to the implication of the seventh and eighth pair of nerves as the result of a fracture traversing the posterior fossa of the skull towards the outer angle of the jugular foramen and cutting across the petrous bone (see [p. 104]).

The ninth, tenth, and eleventh cranial nerves may be injured in the same variety of fracture. These three nerves are, however, so protected by their dural sheaths that they generally escape injury.[21]

In the following cases the nerves were involved:—

The patient was admitted suffering from a fracture resulting from a blow on the posterior parietal region. During the next four days no special symptoms developed. On the fifth day, during a sudden attack of dyspnœa and dysphagia, death occurred. A fissured fracture was found which extended into the jugular foramen, a region occupied by blood-clot.

A man committed suicide by means of a pistol-bullet fired through the mouth. The bullet lodged against the under surface of the petrous bone, tearing the jugular vein and lacerating the nerves passing through that foramen.

In another case the patient was admitted with a fractured base. He progressed favourably until the tenth day when, on sitting up suddenly in bed, he was seized with rigors, dyspnœa, and dysphagia, dying shortly afterwards. A basic fracture was found, practically dividing the skull into two parts and involving the jugular foramen. Displacement had occurred with consequent compression of the ninth, tenth, and eleventh nerves.

The twelfth nerve.

The anterior condyloid foramen is most favourably situated with respect to the course pursued by posterior fossa fractures. No instance of its involvement has come under my own observation.

Stierlein records a case in which the tenth and twelfth nerves were injured, with inability to speak or swallow, paralysis of the right half of the tongue, soft palate, vocal cords and pharyngeal constrictions. Death resulted in seven weeks.

The late Professor von Bergmann[22] mentions a case of hypoglossal paralysis together with paralysis of the sterno-mastoid and trapezius muscles (eleventh nerve).

For treatment of basic fractures, see [p. 116].

Fracture of the Base of the Skull: Summary of Symptoms

Anterior Fossa.	Middle Fossa.	Posterior Fossa.
Hæmorrhages.	Hæmorrhages.	Hæmorrhages.
Subconjunctival. Palpebral. Peripalpebral. Orbital. Retinal. From the nose. From the mouth.	Into the temporal region. From the mouth. From the nose. From the ear.	Into the nuchal region. Into the occipital region. Into the post-auricular region.
Cerebro-spinal fluid.	Cerebro-spinal fluid.	Cerebro-spinal fluid.
From the nose. From the mouth.	From the nose. From the mouth. From the ear.	None.
Brain-matter.	Brain-matter.	Brain-matter.
From the nose.	From the ear.	None.
Air-escape.	Air-escape.	Air-escape.
From the frontal sinus. From the ethmoidal cells.	From the mastoid antrum.	From the mastoid antrum.
Nerve-involvement.	Nerve-involvement.	Nerve-involvement.
Olfactory. Optic. Third. Fourth. Fifth (first division). Sixth.	Fifth (second and third divisions). Sixth. Seventh. Eighth.	Seventh. Eighth. Ninth. Tenth. Eleventh. Twelfth (?).