Differentials

Common

Migraine headache

History

positive family history of migraine; symptoms may be unilateral or pulsing; pain moderate or severe, aggravated by physical activity; may be associated with nausea, vomiting, photophobia, or phonophobia; may occur with an aura[20]

Exam

normal

1st investigation
  • none:

    diagnosis is clinical, and imaging is not routinely recommended

Other investigations
  • head CT:

    negative for intracranial pathology

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  • lumbar puncture:

    absence of blood or pleocytosis; normal opening pressure

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  • head MRI:

    normal brain structure; no enhancement

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Acute sinusitis

History

frontal headache; purulent nasal discharge; facial pain and congestion; fever, cough, headache, fatigue, dental pain, ear pain or fullness

Exam

nasal obstruction, halitosis, facial tenderness

1st investigation
  • none:

    diagnosis is clinical, and imaging is not routinely recommended

Other investigations
  • sinus CT:

    sinus thickening; bony erosions

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Uncommon

Subarachnoid haemorrhage

History

rapid onset of severe headache often described as 'worst headache of my life'

Exam

may be associated with altered consciousness, meningeal signs, or focal signs; may be no physical findings

1st investigation
  • non-contrast head CT:

    bright (hyperdense) signal is consistent with an acute bleed; typically a full appearance of the brain with loss of basal cisterns

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Other investigations
  • lumbar puncture:

    red blood cells present in the first and fourth tubes suggest the blood is pathological and is not due to a traumatic lumbar puncture; xanthochromia may be present, due to lysis of RBCs

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  • cerebral angiogram:

    arterial abnormality identified

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Ischaemic stroke

History

acute onset of headache; focal seizures; symptoms of elevated intracranial pressure (headache, vomiting, depressed consciousness)

Exam

focal neurological signs, focal seizures, altered consciousness

1st investigation
  • non-contrast head CT:

    bright (hyperdense) signal is consistent with an acute bleed; CT may identify large or older ischaemic strokes

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Other investigations
  • MRI or MR angiography (MRA):

    multiple subcortical areas of ischaemia suggests embolic source; MRA may demonstrate an arteriovenous malformation or fistula; MRI (with diffusion weighted imaging) will identify strokes earlier than CT

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  • hypercoagulability testing:

    may be abnormal

  • ECG:

    may reveal a cardiac cause

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  • echocardiography:

    may reveal a cardiac cause

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Parenchymal haemorrhage

History

abrupt onset of headache (thunderclap headache), altered mental status (suggestive of elevated intracranial pressure), may be history of trauma, may be related to vascular malformations (AVM), may be history of hypertension

Exam

altered mental status may suggest diffuse cerebral involvement or haemorrhage within the reticular activating system, or may suggest elevated intracranial pressure; focal neurological signs relate to the location of the haemorrhage

1st investigation
  • non-contrast head CT:

    bright (hyperdense) signal is consistent with acute blood

    More
Other investigations

    Vascular dissection (carotid, vertebral, or intracranial arteries)

    History

    may be history of head or neck injury, the injury may be mild or considered insignificant, and the onset of symptoms may be delayed; presents with headache and neck pain, with or without focal neurological symptoms due to secondary stroke or transient ischaemic attack

    Exam

    focal neurological signs are consistent with a secondary stroke (hemiplegia with carotid dissections and hemiataxia with vertebral artery dissections); neck auscultation may reveal bruits; Horner's syndrome (mild ptosis, anhidrosis, and miosis) is consistent with carotid injury

    1st investigation
    • MRI or MR angiography (MRA) of the head and neck:

      crescentric hyperintense intramural haematoma within the vessel wall on axial fat saturated T1 sequences; may show an arterial cut-off; diffusion-weighted imaging demonstrates areas of infarction

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    Other investigations
    • angiography:

      segmental tapering narrowing

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    Cerebral sinovenous thrombosis

    History

    gradual onset of headache made worse by bending over or squatting, or while straining with bowel movements (Valsalva); vision changes common (e.g., blurring, horizontal double vision, peripheral vision constriction, and transient visual obscurations); pulsatile tinnitus possible; fever may be present

    Exam

    meningismus and/or mastoid tenderness or swelling; focal or non-focal neurological findings; optic nerve oedema; bilateral ocular abduction limitation

    1st investigation
    • neuroimaging:

      hyperdense venous sinuses, haemorrhage, and areas of hypodense brain parenchyma

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    Other investigations
    • FBC:

      possible polycythaemia

    • PT and activated PTT:

      hypercoagulable state

    Postconcussion headache

    History

    history of trauma; confusion; altered concentration, memory, and problem solving; irritability; emotional changes; headaches may take several months to resolve

    Exam

    non-focal findings, except for mild alterations in mental status

    1st investigation
    • none:

      diagnosis is clinical, and imaging is not routinely recommended

    Other investigations
    • non-contrast head CT:

      intracranial abnormality, skull fracture

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    Cerebral contusion

    History

    history of trauma; confusion or personality change; focal seizures; headaches may recur with exertion weeks after the inciting event

    Exam

    focal neurological findings, altered level of consciousness, or abnormal mental status testing

    1st investigation
    • non-contrast head CT:

      dark (hypodensity) if oedema or bright (hyperdense) if haemorrhagic

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    Other investigations
    • MRI:

      FLAIR (fluid-attenuated inversion recovery) hyperintensity consistent with oedema; T2 gradient echo sequences show hypointensity consistent with haemorrhage and may 'bloom' over time

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    Subdural haemorrhage

    History

    usually occurs after head trauma; may be lucid intervals between the trauma and the onset of symptoms, which may develop quite slowly (because often due to a venous bleed) and include headache, seizures, and symptoms related to elevated intracranial pressure (vomiting and nausea)

    Exam

    focal findings on examination, focal seizures, altered level of consciousness, or coma

    1st investigation
    • non-contrast head CT:

      bright (hyperdense) signal is consistent with an acute bleed

      More
    Other investigations

      Intracranial hypotension

      History

      headache is generally diffuse and dull, worsens within 15 minutes of standing, and is associated with neck stiffness, tinnitus, hyperacusia, photophobia, and nausea; may be history of recent lumbar puncture or back/neck trauma; may be associated with Marfan's Syndrome, Ehlers-Danlos syndrome, neurofibromatosis, or polycystic kidney disease

      Exam

      abnormal hearing and photophobia; downward traction may lead to cranial nerve palsies or altered mental status, and may result in subdural hygromas or haematomas

      1st investigation
      • lumbar puncture with opening pressure:

        opening pressure <60 mm H2O in sitting position

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      Other investigations
      • MRI with contrast:

        diffuse pachymeningeal contrast enhancement, evidence of sagging brain, and sometimes subdural hygroma or haematoma

      • CT myelogram:

        may demonstrate diverticulum and localise leak

      Epidural haemorrhage

      History

      usually history of head trauma; often a lucid interval between the trauma and the onset of headache; symptoms related to elevated intracranial pressure (vomiting and nausea); seizures

      Exam

      focal neurological findings, focal seizures, altered level of consciousness, or coma

      1st investigation
      • non-contrast head CT:

        bright (hyperdense) signal is consistent with an acute bleed

        More
      Other investigations

        Meningitis

        History

        acute onset of headache, fever, neck stiffness

        Exam

        positive meningeal signs (Kernig's and Brudzinski's signs), altered mental status

        1st investigation
        • lumbar puncture:

          elevated WBCs and/or elevated protein

        • MRI head without and with contrast, or CT head with contrast:

          rules out haemorrhage and herniation

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        Other investigations
        • latex agglutination:

          positive in bacterial meningitis

        • fungal culture:

          may be positive in immunocompromised patients

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        • Gram stain:

          may be positive

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        • bacterial culture:

          may be positive

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        Encephalitis

        History

        seizures; fever; exposure to infectious agent (e.g., arthropod-borne arboviruses such as eastern equine, western equine, St. Louis, Venezuelan equine encephalitis, and West Nile virus; herpes simplex type 1; lymphocytic choriomeningitis virus)

        Exam

        altered mental status ranging from minor deficits to complete unresponsiveness; focal motor or sensory neurological abnormalities; speech disorders; exaggerated deep tendon and/or pathological reflexes

        1st investigation
        • lumbar puncture:

          elevated WBCs and/or elevated protein

        • MRI head without and with contrast, or CT head with contrast:

          rules out haemorrhage and herniation

          More
        Other investigations
        • EEG:

          generalised slowing or disorganisation are consistent with encephalopathy; rules out subclinical status epilepticus in the unconscious patient

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        • fungal culture:

          may be positive in immunocompromised patients

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        • viral culture:

          may identify causative virus

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        • PCR:

          may identify causative virus

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        • serology:

          may identify causative virus

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        Dental caries, gingival disease, or abscess

        History

        pain typically localised to the mouth; may present as facial pain or headache

        Exam

        caries, gingival disease, abscess

        1st investigation
        • none:

          diagnosis is clinical; patient should be referred for dental consultation

        Other investigations

          Brain tumour

          History

          indolent progressive headache, nausea or vomiting, difficult walking, visual symptoms, focal weakness, or personality change

          Exam

          optic nerve oedema, cranial nerve abnormalities, ataxia, abnormal reflexes, visual field or acuity defects

          1st investigation
          • head CT:

            tumour

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          • MRI without and with contrast:

            tumour

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          Other investigations
          • lumbar puncture:

            tumour cells

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          • brain biopsy:

            tumour

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          Temporomandibular disorders

          History

          temporomandibular joint pain, noise in the joint (clicking, popping, or crepitus with/without locking), masticatory muscle tenderness, limited mandibular movement;, headache in the temporal region, otalgia and/or tinnitus without a significant ear disorder​​; associated symptoms, such as myalgia and arthralgia, depression and anxiety may be present

          Exam

          pain may be triggered by jaw movement or pressure on the masticatory muscles, and may be associated with jaw click or reduced jaw movement; maximal mandibular opening is 35-55 mm, movement may be reduced to <35 mm; there may be an uncorrected deviation on maximum mouth opening; wear facets are indicative of bruxism

          1st investigation
          • none:

            clinical diagnosis; requires dental referral

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          Other investigations
          • MRI:

            disc displacement

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          • CT or cone-beam CT:

            cone-beam CT shows flattening of the condyle, osteophyte formation, erosion of the cortical bone, cortical bone changes, sclerosis, condylar fractures, joint space changes.

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          Tension headache

          History

          often milder headache that is diffuse or posterior in location;[20] no associated migrainous features (nausea, vomiting, photophobia, phonophobia) or autonomic features

          Exam

          neurological examination is non-focal; trigger points may be identified in the neck

          1st investigation
          • none:

            diagnosis is clinical, and imaging is not routinely recommended

          Other investigations

            Indometacin-responsive headache

            History

            unilateral, severe, boring headache lasting 20 minutes occurring 10 to 40 times per day with autonomic symptoms such as nasal congestion, lacrimation, and conjunctival injection; or unilateral headache lasting hours or days associated with milder autonomic or migrainous symptoms

            Exam

            non-focal neurological examination

            1st investigation
            • MRI with and without gadolinium:

              normal

              More
            Other investigations
            • indometacin trial:

              headache improves quickly with indometacin administration

            Medication overuse headache

            History

            drug history of ergotamine, triptans, analgesics, opioids, or a combination of these medications; headache has developed or markedly worsened during overuse; headache resolves or reverts to prior pattern within 2 months of discontinuation of overused medication

            Exam

            neurological examination is non-focal

            1st investigation
            • none:

              diagnosis is clinical, and imaging is not routinely recommended

            Other investigations

              Cluster headache

              History

              stabbing excruciating headache, often at the orbit, that lasts 15 to 180 minutes and occurs 1 to 10 times per day, often daily for several days or weeks, then resolves for several weeks or months

              Exam

              neurological examination is non-focal; autonomic features are present, including lacrimation, conjunctival injection, nasal congestion, ptosis, and eyelid oedema

              1st investigation
              • MRI:

                normal with cluster headache

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              Other investigations
              • oxygen supplementation:

                resolution of headache

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              New daily persistent headache

              History

              headache for more than 3 months that is unremitting and occurs daily from within 3 days of onset; mild to moderate intensity, bilateral in location, and not worsened by routine activity; may be migrainous features

              Exam

              neurological examination is non-focal

              1st investigation
              • MRI:

                normal

                More
              Other investigations
              • lumbar puncture:

                normal

                More

              Intermittent hydrocephalus

              History

              intermittent severe headache

              Exam

              signs related to elevated intracranial pressure such as optic nerve oedema, abducens nerve palsy, or altered mental status may be present, but may not be present if obstruction is brief

              1st investigation
              • non-contrast head CT:

                mass lesion may be present; hydrocephalus may be present

                More
              Other investigations
              • brain MRI with and without contrast:

                mass lesion near the ventricular system

              Pseudotumour cerebri (idiopathic intracranial hypertension)

              History

              headache made worse by bending over or squatting, or while straining with bowel movements (Valsalva); vision changes common (e.g., blurring, horizontal double vision, peripheral vision constriction, and transient visual obscurations); pulsatile tinnitus possible

              Exam

              non-focal examination findings; optic nerve oedema, bilateral ocular abduction

              1st investigation
              • non-contrast head CT:

                normal

                More
              • lumbar puncture:

                elevation of the opening pressure >250 mmHg

                More
              Other investigations
              • MR or CT venogram with or without contrast:

                venous outflow obstruction

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              • MRI head with and without contrast:

                may show secondary signs of increased intracranial pressure such as an empty sella, dilated optic sheaths, tortuous or enhancing optic nerves, and flattening of the posterior aspects of the globes

              Ventriculoperitoneal shunt dysfunction

              History

              headache worse when supine; horizontal diplopia; history of trauma near track

              Exam

              new focal neurological signs; Cushing's triad of hypertension, bradycardia, and irregular breathing pattern; pupillary asymmetry; elevated intracranial pressure (altered mental status, horizontal diplopia, optic nerve oedema); evidence of disruption or tunnel infection (tenderness or erythema over the track); tenderness to abdominal palpation; ascites; acute abdomen (distal aetiology)

              1st investigation
              • non-contrast head CT:

                shunt disconnection, malposition of the shunt catheter, or enlarged ventricles suggest shunt dysfunction

              • shunt series x-rays:

                imaging of the shunt in the neck, chest, and abdomen may reveal disconnection as the aetiology of malfunction

              • neurosurgical evaluation and possible shunt tapping:

                if a reservoir is present, measurement of pressure may be indicated

              Other investigations

                Pituitary apoplexy

                History

                headache that is often acute onset; visual impairment (often diplopia)

                Exam

                ophthalmoplegia, shock

                1st investigation
                • head and neck CT:

                  sellar or suprasellar hyperdense mass

                Other investigations

                  Hypertensive encephalopathy

                  History

                  acute or gradual onset of decreased alertness, vision changes (blurring or obscuration), and seizures

                  Exam

                  examination may be limited by mental status change; hypertension

                  1st investigation
                  • head CT:

                    may show patchy bilateral areas of hypodensity with a posterior predominance

                    More
                  Other investigations

                    Occipital neuralgia

                    History

                    posterior or calvarial headache, pain with neck/shoulder movement

                    Exam

                    tenderness over occipital condyles

                    1st investigation
                    • no initial test:

                      clinical diagnosis

                    Other investigations

                      Facial neuralgia

                      History

                      sudden lancinating unilateral facial pain

                      Exam

                      normal examination

                      1st investigation
                      • no initial test:

                        clinical diagnosis

                      Other investigations

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